I had 5 children and the last one made me very uncomfortable. The only way I could sleep some weeks was to sleep in a recliner. I hope you aren't working during the day because if you can't sleep at night then you need to get a nap during the day. Try everything. A comfortable sleep bra, pillows supporting knees, tummy, reading a dull book, etc. What works this week may not work in two weeks time, but conversely what doesn't work now may work like a charm in a week or two. Tell your doctor - he/she should be a good partner in your well being and sleep in SO important.
I would guess a lot of your discomfort is based on the position of your baby and you can't do anything about that, but I found that talking to the baby and playing music for him helped both of us to settle down. Good luck.