So im really depressed right now, and i need advice on how you motivate yourself to lose weight?

So im 15, and 5'2" Last year I weighed 119-126, and now im almost 145 and i just keep on gaining and gaining and its really getting out of hand. I don't understand, bc last year i stopped drinking soda, and i stopped eating french fries, so when i try to be more healthy it just backfires, Its just really depressing for me, bc i cant wear tshirts bc i feel self concious, so i usually just wear hoodies all the time, but now that summers coming i know im not gonna be able to do that. And last year guys liked me and now nobody likes me, i just feel awful about myself bc im so ugly and disgusting. I know this should be enough to make me wnat to lose weight, and i want to really bad, but its so hard, how do you do it! It's just so effing hard for me, and i seriously feel awful about every aspect of me. I realy want to lose weight this summer, really really bad, can you help me, please!