Pathological fear of food (TW eating disorders maybe)

Sam • apparently dating a sprouse triplet
So I'm 20 but in my 17th-19th years of life I had a pathological fear of food and gaining weight. I didn't want to be above 120 and I've been 5'5" for like five years. It's a healthy enough weight. However I was always told I was way too skinny. I actually wanted to be skinnier and I could've been under 100lbs if I wanted to and tried hard enough. I was about 118lbs for awhile in high school and my first year of college when I lived on campus. I didn't eat much or exercise so I didn't gain or lose much weight. 
Then in my second year of college, which I just finished, I lived at home and I'm currently 134lbs. It's because of the easy access to food. I used to be able to turn off my hunger but since I had food so readily available and a lot of free time I could eat whenever I wanted and so I gained 16lbs in a year. I realize this may seem insignificant to others and people will probably be like "oh please, 135lbs is not large" but to me it's completely unacceptable. I hate it so much. I always feel so large. None of my dresses fit as well as they used to, I have flab and cellulite, and I look in the mirror and see how my belly looks and I want to cry. It's not even that much of a difference and I know it, but I still can't stand it. Now I don't want to eat at all and I want to go to the gym constantly. Whenever I eat I feel ashamed and immediately regret it. I thought I was recovered from the fear of food but I'm really not. I can feel it coming back and I'm about ready to turn off my hunger again and only eat when I'm required to from my dad. It just sucks because I thought I could control myself better, and I'm going to be way too extreme and probably aim for lower than 118 because I can easily just starve myself to get there. I don't know if it's an eating disorder or what. I don't know how to even feel about myself right now.