Gaining Weight

So recently I've noticed that I've gained weight in my stomach area because I've been eating a lot. I've been eating so many sweets and I just can't seem to control my appetite anymore. Even when I'm not hungry I eat. And I have no motivation to exercise even though I know I need to. And before you jump to any conclusions, there is absolutely no way I'm pregnant (abstinence and all). So does anyone have any tips to sort of get back on track? I'm getting really self conscious especially now that summer is just around the corner. Thank you!