Vortex, when it comes to exercise, the best advice I can give is to find a form of physical activity that you actually enjoy. Don't go looking for the one that you think will be the most effective or the most efficient, because if the motivation isn't there, then the whole endeavor will probably fall to pieces somewhere along the line.
Find something that's enjoyable and that makes you feel good. That's obviously what JedExodus has found with walking; he's found a form of exercise that is both effective and fulfilling. When you discover that particular activity that's right for you, then it'll probably lead on to a greater sense of contentment, and perhaps even happiness.
If possible, I'd definitely suggest trying to go for regular walks, out and about. I really think that it would do you good, not only for the fitness side of things, but also (as JedEx pointed out) for the opportunity to see more. To even experience more of the world around you is a really nice thing. When you're confined to your own little corners of the world, things really can get monotonous. It's unhealthy to only ever experience the same few environments, to dwell in the same point A's and B's repeatedly, without ever seeing the rest of the world. I urge you to find a way of experiencing more; break the tedium by going out and seeing more. Besides, it's only when you stop, slow down for a second, and properly survey your surroundings, that you actually realize how much is going on in the world around you. There's a lot of life out there; an infectious buzz to the world that you'll miss out on if you ignore it, or let it pass by unnoticed.
Read that instead ^.