Hi Cazzy, welcome. Guess the obvious ones are using light weights and resistance bands. These should help up your metabolism. Wish I knew enough to work out a routine but there are a few fitness trainers who post that will be better able to advise.
I would generally brake the body into sections. Biceps, triceps, chest, abs, obliques, shoulders neck and back. Find two or three exercises to to target each one that you feel comfortable doing and start with say 3 or 4 sets of 8 repetitions with 30s rest between each set. Take a minute between each exercise type. When 8 is less challenging go to 10 then 12. After 12 up the weight. Should be possible to get some dumbells or a small kettlebell from most supermarkets or online stores. Maybe do front one day ( biceps, chest, abs) back the next ( obliques, shoulders, triceps, neck ) then rest 3rd.
Also, its probably going to sound a bit mad, but don't dismiss yoga. There are many breathing exercises and muscle control ( Bandhas ) that can be done seated or prone. There is a great abdominal technique called Uddiyana and the more advanced Nauli which could be useful to you. Also looks really cool when mastered. Will freak future partner right out
Hope some of that is helpful. There was also guy in the 30's did a lot of work on exercises for people with limited movement. Am sure his name was Moshe Feldenkrais. Might be worth a bit of researching. Have some of his books but sadly not got around to reading them yet. Anyway good luck and please post to let us know how you have got on.