Smoking aside, I don't really think that I've had to give up much to be honest, I ditched a lot of the overtly macho stuff years ago at the time of rehab because I knew then that it just wasn't me. I have found changing relationships difficult at times as I quite liked a lot of my guy friendships and although they are still good and a lot more honest, it does feel a little odd sometimes.
Ayaname, I did martial arts too when I was younger and know what you mean about it being a very macho environment, I couldn't even imagine going now, but at the time it was all about me trying to prove that I was all man (even though I knew that I wasn't). My sifu was called Trevor and was one of the nicest men that I have ever met, but I still couldn't imagine it.