Paraplegic needs help

As indicated, I'm a paraplegic. I have spina bifida and I cannot walk. This is making my weight loss journey frustrating as heck. Since I am sedentary most the time other than pushing my chair, I do not get in as much exercise as an able bodied person. I also have severe back issues from years of surgeries. I'm 32, I have a 10 year old that I'm too exhausted to keep up with and I'm sick of it. I used to eat once a day, or not at all. I'm trying to retrain my body finally to where I'm able to eat more without feeling like I'm going to vomit. I've set my goal at 1200 calories a day, but I'm not even hitting that mark. I feel too full, especially now that I'm drinking more water. I've cut out soda and coffee to a large extent. I used to drive through Starbucks or Dunkin Donuts every day. I've unintentionally stopped eating red meat, limiting my bread. I love pasta, but now I eat less and make sure it's whole grain. I live in New Mexico and we have trails out here everywhere, however, 99% are inaccessible to me. I can't afford a gym. I use weights at home, but I I feel it's a waste because I don't know what will help with weight loss, plus I have to take into account my horrible balance. I'm just stuck. Thanks.