Yes, you can exercise. You can do isometrics, Callanetics and deep breathing (called Oxycise) and even upper body weight lifting and leg lifts can be done from a chair. All of those will help build muscle and raise your metabolism. Also, if you will cut out sugar, most of your white flour and drink tons of water it will help with weight loss - and don't eat after dinner at night.
Isometrics (for those who don't know) is simply a technique of tensing, holding and releasing a group of muscles. It builds muscles without actually having to move around and it really works. Callanetics works much the same way but deeper. It's a deep muscle exercise routine developed by a woman named Callan Pinckney. She has a book and tapes you can buy (or get from the library). She has positions you get in and hold for different muscles groups. I once lost 15 inches doing Callanetics so I KNOW that works. I've had 2 knee surgeries and a bad back so if I can do those most people should be able to. There are a lot of the positions I couldn't get into because of my knees so I just skipped them and I still lost the inches. I love Oxycise ... it's painless! You just get in a stretching position, take a deep breath and hold it. It also works. You lose weight, inches and tone up. So there is help out there, you just have to know where to look for it. You can find the Oxycise tapes at
http://www.oxycise.com ... I suggest you start out with the first one. That's the best one and the easiest one for people with health problems. You can find Callan Pinckney's tapes and books here:
http://www.callanetics.com/booktape.htm ... you can buy a booklet on isometrics here:
http://www.trafford.com/robots/02-0449.html . I wish you much luck with your weight loss ... but it takes more than luck. It takes renewed determination each morning when you get out of bed and enough will power to last you all day long everyday ... and even more for those of us with health problems and the added problems of medications. We just have to rise above all the temptations out there and keep reminding ourselves that our lives are not just about the FOOD! I have a 12 week self-improvement program on my site you might like to look at:
http://www.memeart.com/12weekhome.html
Just try one or two of the exercise above, gradually, and add a couple of extra bottles of water a day, cut back a little on the amount of food you are eating and see if you don't feel better about yourself in a few weeks! Let me know how you're doing!