I agree with the many other answers with regards to lots of pillows especially when it comes to a body pillow. P. one between the knees, 1-2 at your back, a smaller pillow between the belly & the mattress to lift the weight from the baby and perhaps another smaller pillow to scrunch under your lower back to pelvic area to alleviate the pressure there. At 35 weeks, your baby is literally sitting in your pelvis. This is why you are having such a tough time getting comfortable. BTW, you might also want to try sleeping in a recliner with lots of pillows too. I had to do that for a while as well. I couldn't sleep with my husband by my 2nd trimester with either pregnancy. Plus, I was on bedrest with both my girls from the time I was within 3 months gestation all the way through until the end, which both were well overdue although not for lack of trying to come entirely too early throughout the entire pregnancy.
Here's a great trick for intermittent back pain. It was a tip given to me by my Lamaze couch the first go around...
If you have a rolling pin, yes the kind you use to make biscuits or pastry, and that rolling pin is the type where the center spins on a dowel that goes through the center section to the handles, have your husband or friends or even other children roll the rolling pin over your back with you standing holding onto the back of a sturdy chair slightly bent over. It feels like total and complete heaven! Tennis balls work too but I found with both children and my first I had severe back labor, which turned out that the baby was sitting in a back-labor position in the latter weeks after she went head down into position before birth, the rolling pin worked best.
Also, find an empty wall, P. both hands open with palms on the wall, bend your body forward slightly to then curve your back outward such as how a cat does when it stretches after a nap... When the cat's back arches upward. This will help stretch those muscles that are pulled tight from the added weight of the baby being so far down in the canal.
Unfortunately, this late in the game, you will find that there are few times when you actually don't feel exhausted and as if you are carrying around a 10-lb weight out front because in essence, you are. Try these few things to see if they help.
Important things to avoid: Hot baths, hot tubs, and heating pads without advice from your doctor. These things can be dangerous for you as well as your unborn child. Talk openly with your doctor about the pain and if possible, contact a local Lamaze coach for more ideas. My girls are 23yrs old and 13 yrs old. In fact, my oldest will be getting married in August of this year so it's been a long time since I did the Lamaze and the breast-feeding thing but it was well worth it - both of them.
For all you moms out there, I would highly recommend breast-feeding. There is something nobody seems to tell new mothers when they give birth but I'm going to share because it was such a wonderful experience for me.
I'm sure everyone has heard the old saying that after your baby is born you sleep when the baby sleeps. Don't try to clean or catch up on housework or such after you have your baby down for a nap. You will be exhausted from night-time feedings, up at all hours, possible colicky babies, etc... I discovered while breast-feeding that not only did the sucking action cause my uterus to contract back to it's original size faster, lessen chances of becoming pregnant again after having had a baby before going back on some form of birth control, and let's not forget the antibodies the baby gets from the colostrum then the actual milk that comes in after a few days or so of breast-feeding..... There is something even better. While breast feeding, there is some type of hormonal release in the mother's body that affects a section of the brain that creates an odd, difficult to explain but wonderful feeling of exhilaration and ease of sleep.
My second child had such a strong suck reflex that whenever I fed her, I had to get us situated in such a way that we could doze off together because while nursing her, that chemical reaction hit and within no time it was like I was on some type of natural anti-anxiety high. Not only did my daughter fall asleep faster but so did I. In the first 5 years of this child's life, she was only sick 1 time each year. For some stupid reason it always managed to come around her birthday but that was it and she was and has rarely been sick since.
If it hadn't been for the chemical release during nursing, I would have never had decent sleep when I was feeding her. This baby (my youngest) nursed every hour on the hour for months but I had the greatest dozing sleep but good sleep if that makes any sense at all than I had with my first pregnancy. It relaxed us both. In time, it seemed to make it easier to slip her into her crib in her room after nursing the last time for the night because she was zonked out before I finished burping her. In fact, I often burped her while she was sleeping then snuggled her in her crib in the wedgie and she slept like a charm as did I. Best of all too, there were no bottles to wash, fill, mix, or buy. I only had to purchase a few bra pads, which I washed in Wool-lite in hand-wash mode in my front loader. I had the nursing bras, a few nursing shirts, and a baby sling with a nice breathable yet covering blanket I carried anytime we went out in case our outings ran into her feeding times. People were a bit funny about it at first but after a while, it became second nature for people to see me out in public in a restaurant at a quiet back booth with my husband, our children, and my infant in a babysling where I could enjoy a meal while not interrupting her mealtime either when we went out as a family. Did I mention the milk was cheap too? It was free. All I had to do was stay away from specific medications especially aspirin and watch the spices and such because it does cross over into breast milk. If you want spicy foods, I'd suggest that you pump milk for a few spare feedings so you can express the spicy milk then immediately return to nursing. Breast milk is freezable too. Just tie the milk in those plastic baggie playtex nurser inserts then freeze but use within a few weeks by heating it to the temp of your inside wrist or a touch warmer then hold your baby closer to your bare skin or he/she may not take to a bottle after having been breast-fed.
Hope this helps. I know I got a bit off topic from back pain but I just had to share the experience with that chemical release that comes with nursing. check out the Le Lache League for more information. They are online and have phone numbers you can call for assistance. A prime example of assistance is like the time my milk refused to let down and I became engorged. The nurse through LLL had me run a really warm bath and before I could step into the tub my milk let down. I had my husband bring me the baby and she was able to latch on without any problems. I didn't have engorged glands so this helped her problem of being hungry and my problem of having too much milk before my milk production became adjusted to her nursing schedule. It was a great bonding experience too.
Best of luck to all new mommies whether it's your first or your multiple child/children (if any twins, triplets, etc... in the mix). Enjoy them while they are babies because they grow up so fast. It's like one moment you're nursing them, then reading stories, entering kindergarten, and the next they are on the verge of college graduation planning their wedding and working full-time with the company that chased them all through college... or a year plus into middle school and that's your baby, the last in the nest after the first one has found her wings.