Please help me out

I have just turned 16. For years I have struggled with my weight and my view of myself, since I was in 1st grade,I am now in 10th.i started trying to loose weight in 6th grade in the bad way, starving myself, working out everyday for hours, and lost a lot of weight. But I gained it back, and it’s like a cycle for me, i gain weight and feel terrible and try and starve myself and it doesn’t work. I have been avoiding my weight for a little while maybe a couple months now, and I feel the cycle starting again. It’s always in my head constantly, but I haven’t been doing anything about it. But I got into a relationship a month ago and it is destroying my self esteem being over weight, I want to look good for him, he deserves someone who is pretty. I feel so gross all of the time, hardly ever good about myself. I want to try to loose weight again, but I hate the cycle that I am in. How do you get out of it? I just want to loose weight and be happy. Since Halloween was just a bit ago, I have been eating candy every day. I want to be skinny but I have such a hard time doing what I should be, aka not eating too much, working out. I always get super sad and have no motivation :(