As above. Lifting is probably the best thing you can do for yourself. I've been lifting for the last two months, and so far I've gained a slight bit of muscle, and lost a bit of fat. The main difference though is how great I feel. I feel happier, more confident, and have less joint pains (though lots of muscle pain). The saying is no pain no gain - that applies to muscle pain, not joint pain, muscle pain is good, joint pain is just bad and you need to fix that.
The last two weeks I've also started doing 40 minutes cardio every night. Cardio is great, but you can't be afraid to sweat. I lose about 200grams of body weight a day.