It sounds like you're doing great, actually.

I would suggest a newer, easier-to-use bike, but I see you've already posted another thread about that!

Get a copy of Jayne Williams' "Slow Fat Triathlete". It will make you laugh your head off and teach you to stop worrying about how you look. She did her first tri---if I am remember this right---when she weighted 220 lbs. She has done many since, including a half Ironman, I believe. She is a total hoot.

http://www.slowfattriathlete.com/