Son, irrespective of your health my friend don't take on all this guilt.
You are so limited to what you can do in your life.
Playing Grand Theft Auto is not a sin as others might think:)
You have made a commitment before God and that is between you and our saviour, no-one else.
Games are just that, games.
You are not going out committing sin so in Gods eyes you are being a Christian.
My sons play Grand Theft Auto and enjoy it for it is only a "game" so enjoy it my friend. You are so limited to what you can do as a young man where my sons are not and yet they play all sorts of games but they don't turn my sons into criminals:)
You sound to me as a nice person, God will not judge you for playing anything unless you sin but you are not sinning.
Enjoy your life to the full, as much as you possibly can.
A little p 0 r n o g r a p h y does you no harm unless you allow it to take over your life.
We all have a gut feeling when we do something wrong and that is your righteousness steering you as a Christian.
You are not here to be judged by man, only God, for He truly loves you my friend don't ever forget that.
I pray that you heal and one day be able to lead a normal life, bless you.