Hi B.,
Congratulations on making good progress so far! You've lost a bunch of weight, and have started making some healthier choices (reducing the diet cola, baking instead of frying, etc.)
Read the book Ultra Metabolism (I forget the author, I think it is Dr. Mark Hyman but not sure). Or listen to it on CD while you walk the treadmill. Lots of good stuff in there.
With the nausea, could you be pregnant? It would be difficult and unwise to lose weight if that is the case.
Maybe you need to switch your form of exercise or walk somewhere else besides the treadmill. If you walk outside, you get different scenery, also can you find a place to walk up hills? or on sand? I don't have a treadmill but I do notice a difference in walking those places versus walking on the flat roads.
If your knees hurt now, jogging will only make them worse. Can you swim somewhere? or do water exercises? My mom loved those--they were held at a local high school pool during the day (while kids were in class). They did exercises (leg lifts, kicks, etc) while in the pool. Even just walking in the water burns calories, you have to push against the water, but because the water also supports some of your weight, it is easier on joints. Plus it's cool in summer!
Someone else mentioned a stationary bike being easier on knees; you could get a regular bike and go outdoors too.
My cousin swears by Weight Watchers. It does cost money but I don't know how much.
Does your local hospital or clinic have a weight loss support group? you could check into TOPS (Take Off Pounds Sensibly) another support group. There's also Overeaters Anonymous. Maybe there is an online group somewhere?
Ask your doc for advice next time you are in for something else. Might nausea be a side effect of some of your meds, and could you switch to different ones?
Have you thought about yoga? It's great for flexibility and stress reduction. If I had all your medical conditions, I'd be stressed!
chiropractor for the joint pain?
Keep up the good work on reducing the sweets, artificial sweeteners and junk food. Load up on fruits and veggies, then you may be too full to want junk food.
To make water a little more attractive--I use a Brita filter because I hate the taste of our tap water especially in the summer. It helps. Sometimes I also get a lemon or lime and cut it into small wedges. I squeeze the juice from a wedge into my glass of water, then drop the wedge in too. Gives a little flavor with virtually no calories. Usually I eat the wedge when I get done with the water.
Get a walking/biking/diet buddy, either someone you actually get together with, or via email, keep each other honest.
Do you like to play any sports? Are there any you'd like to try? now might be the time.
Dancing burns calories too, I like it lots better than working out--lol!
Look for ways to "sneak" more exercise into your day--stairs instead of elevator, park your car far from the store, etc.
Sorry to run on, hope that helps! Good luck!
K. Z.