it sounds like you just have a lack of motivation to me. Congrats on overcomming everything in your past. But you need to foget that part of your life and stop using it as a cruch to lean on when you dont want to go the the gym. If you REALLY want to change yourself for the better, then you will. If you sit your ass on that couch your only going to get fatter, (ecspecially if tyour running a cycle and not working out)

so heres some motivation: Your gonna be a fat old man if you dont get your ass up

also you might want to look into some kind of boost before the gym mabye? like a redline or some kind of energy boost. sounds like you might need a little of that as well.