That may be hard. The one thing I would recommend is to find a partner to workout with to start. Your goal should be to do the amount you want to work out for about a month or longer. At that point it will turn into a habit. At least I find that working out is an amazing stress relief. I feel so much better after a good hard workout, mainly running. For some reason weight lifting makes me grumpy.
A partner helps a lot. That way if you skip a workout you are not only letting yourself down but them as well. Another suggestion is to not worry about the numbers on the scale. The best way to reach your goal is to workout because you want to be healthier not because you want to get to X lbs.
I haven't stepped on the scale in months. I am in shape though. I track my body fat % rather than my weight because my weight is much higher than other girls my height and size due to the muscle.
I can't give too much help on diet because I am terrible about it. I eat what I want to. Food is something I enjoy and I workout pretty hard so I can enjoy it without worry. I love cake and candy. A big burger with cheese, bacon, and egg with fries, that is one of the meals I can always eat. I tried dieting and it made me miserable. I was tired and always cranky. Now I have so much energy and I haven't gained any of the fat back.
A little tick I use is also trying to trick my mind into enjoying working out. But rather than telling myself "I have to go workout after work" I tell myself "I get to go workout after work!" Going to the gym benefits no one but me. It is something that is completely selfish.
Oh god I keep thinking of things, sorry for the long post >_> One thing I always think of when I don't want to go is that it will take forever but really it doesn't. A good workout can be about 30 minutes.
Sadly I can't offer too much about the medication. I don't know if there is much you can do. But working out can be a stress relief and I told you some of the ways that I can convince myself to actually do it, because I don't want to half the time. Just putting my workout clothes on is enough sometimes.
My Facebook Page