Stay at home mom w/ severly disabled infant & trying extremely hard to lose weight, PLEASE HELP!?

I am in dire need of finding a way to lose weight while taking care of my severely disabled 15 month old (severe CP & brain damage). She cannot sit up, crawl, walk, etc...vomits all the time, and I find myself sitting with her constantly so she can be upright as to not vomit. 3/4 of my day is spent sitting and trying to magage her through seizures, body stiffening, etc...and I am exhausted by the time she lays down for a 2 hr or less nap. (doesn't sleep through the night either due to muscle stiffening and tremors). I had weighted 113lbs when I got pregnant and now am at just under what I weighted at full term. It is hard to make meals, as I usually have to grab and go get her again (as I lay her down quickly for 2 minutes or less) and that is how I can eat during the day...whatever is quick and easy to manage while holding her. I know this might seem hopeless, as it has to me, but I have hope someone out there may have some suggestions for me...I want to stay energetic and healthy for my little angel, as she depends soley on me, I cannot be at my best for her if I don't lose some weight and soon! PLEASE HELP!! God Bless!!