exercising with an illness

Basically i have something called Meniere's disease which means a few days a week I'm unable to exercise and literally have to stay in bed. I can control my calories via my food intake but it's difficult to tone up etc if I can't have a consistent exercise regime. So my question is, the days I can exercise, whats the best thing to do?. I am just over 18Ibs away from my ideal weight, most of this weight is on my thighs so I would like exercises to target these areas. I'm aware that weight loss is everywhere and can't be targeted to certain areas but I would like a good work out regime for the thighs as well as all over.

Height 5.7"
Start Weight: 12.9 stone
Current Weight: 11.4 Stone
Ideal Weight: 10 Stone
BMI: 25