I know its a mental thing but i cant get accept it?

I've become fifty pounds over weight and its deppressing me. I can't seem to start running or eating right. I just can't accept the fact that its gonna take a long time to lose the weight. Someone said it took them seven months to lose 30 lbs. That seems ridicously way too long. This is so weird to me about eleven months ago I was skinny and energetic and now my health is indecline and I get tired easily I really got big. ... I have no hope and don't have a positive attitude about my situationn at all. I should feel good about myself I'm only 22. I just can't believe I did this to myself