A friend of mine was badly injured in Afghanistan, although he's making good physical progress he struggles more mentally. I have to say I think the people he's surrounded by make all the difference, as well as meeting other people and seeing their progress. He certainly has an amazing attitude towards his life. It's a huge inspiritaion.
I got a cracking spin bike from a local gym after they moved premises. It's a godsend during winter when the bad weather hits, plus my local gym doesnt do classes that fit my schedule. It did set me back a fair bit though. I also have a punch bag and weight bench which were pretty cheap and I do actually use them and not for hanging clothes on.
I found basic leg strengthening exercises quite helpful and a foam roller to stop muscles getting too tight. Make sure you are wearing the proper shoes for your gait, and go to your GP if it keeps up or gets worse it could be some kind of muscle strain.