I did shadow boxing when I was stuck in the hospital for 10 weeks. That kept me roughly in a shape other than round. Push ups, sit ups, planking, jump roping, mountain climbers, burpees, sun worshippers, etc. all help too though in the end, I don’t think they really ever top the benefits of doing stuff outside, even if it is in the backyard.
Anyway, try finding an exercise routine you like/don’t hate as much the others and stick with it. Make it a habit, takes quite a while but eventually you probably won’t give it a second thought. And then perhaps after a while, you’ll feel comfortable with walking and maybe even jogging outside. My habitual exercise is running, and I used to hate running, it was soooooo boring to me. And then I found out about mud runs, tough mudders, and other obstacle course related run and now running has just become a part of keeping myself in shape to take on these challenges (which I do find fun).
Point is, perhaps you might need a goal, find some sort of activity you might be interested in partaking in for the hell of it and try to get yourself in shape for it, and if you enjoy that activity, then keep up the exercises for the next time something comes up.