M.B.
My baby was JUST like this!
First of all, at this age, these aren't habits. Babies don't start to form associations and routines until about 3 mos, so don't worry that you're creating bad habits at this age. It just isn't developmentally possible. You're still in the stage where you need to do whatever work. I definitely believe in the "4th trimester"; for the first 3 mos, my baby needed to be held and shooshed and rocked constantly. I didn't do anything special to "break" her of it, she just grew out of it around 2.5-3 mos. Give your baby some time and some grace until then.
Mom instincts are AMAZING when it comes to co-sleeping! We always started the baby in a Rock N Play for the night, but she usually ended up in our bed after her first or second feeding because she slept better that way. The research seems to indicate that, unless the mom is under the influence, co-sleeping is very safe. I had some of the same concerns you did, but I found one night that I startled awake because I was going to roll over onto her. I hadn't even begun to tip yet, but something deep inside of me startled me out of a deep sleep just because I was THINKING of rolling. I really believe we're created to know where our babies are to protect them even in the deepest sleep. Also, we had no problems at all transferring to the crib around 3 mos!
I agree this could be a growth spurt -- my LO went through one around this age. It took a few weeks, and I was exhausted during it, but they don't last forever! During the growth spurt, I co slept the whole night since she was so hungry, and it made nursing much easier.
A few recommendations -- try having him sleep in a Fisher Price Rock N Play next to your bed. It cradles the baby and keeps the head inclined (reducing the startle reflex), both of which really helped my baby to sleep on her own. Keep swaddling, and play LOUD white noise all night long (they say the womb is so loud it sounds like there's a vacuum cleaner running in there! White noise is very soothing, but it has to be pretty loud). Try having him nap in the swing, or transfer him from the Ergo to the swing while he's sleeping. The swinging may keep him asleep (my baby often ended up in the swing with the carrier unbuckled but still underneath her!)
Around that age, I also started putting my baby down for naps, and found that she slept much better and was happier when she was well-rested instead of just waiting for her to pass out on her own. After she'd been awake about an hour (the recommended max time for wakefulness at that age), I'd swaddle her, put her in the rock n play, turn on loud white noise and give her a pacifier. I'd often have to rock the rock n play, but she started falling asleep on her own that way. If it doesn't happen this early for you, no problem! It will. But it may be a good time to start trying.
ARound that age, someone told me, "Their phases pass so quickly at this age! Whether it's good or bad, it won't last long!" It's so true. This will pass, and you will probably find that he starts to grow out of some of this pretty soon. It's hard to imagine now, but later -- when all he wants to do is crawl around by himself on the floor -- you will look back on these days (when all he wanted to do was be held) and wish for them back!