170lbs... and I feel awful

I really want to lose weight before prom which is may 10th, obviously i know im not going to lose a ton but its really hard for me to lose weight and not to make an excuse,, but I have a bad habit with food and binge eat and eat bad food because they make me feel better. I dont go to the gyms near me people some of my friends at school do and thinking of seeing them there makes me embarrassed. im getting to the point where i dont even want my boyfriend to see me without a shirt on.. please any suggestions im 17 and this is the heaviest ive ever been