Lacking Support System

After gaining a scary amount of weight for my height in a short amount of time due to steroids (needed for my lungs to get better) and poor exercise habits I have tried working out while counting calories, counting carbs, quitting soda, quitting fast food and the 17 day diet. I know results are slow to show and you really just have to stick with something but it seems the only thing I'm good at is getting discouraged. I'll lose a few pounds and then a holiday or special event will arise and I'll gain it back and then some. That's when I feel hopeless and give up. I'm only 21 and am now 230lbs, the heaviest I've ever been. I'm honestly terrified about my health. I guess what I'm getting at is I'm thinking maybe I need to be held accountable because I'm the kind of person who hates to let others down. Or just some outside encouragement.

Feel free to add me or just reply here with any advice or ideas, thanks.