I feel like nower days we need a label and diagnosis to feel things. I think it’s a good thing going to the doctor, he will probably refer you to counselling which will help raise your self-esteem which will help with the negative thoughts about your body. I actually have a similar issue to you, broke down yesterday because I couldn’t fit into a size 12, couldn’t even look at myself in the mirror. Depression is more to do with negative thought patterns as a whole; I hate the way I behave, I’m an idiot, I’m useless etc. It also effects your appetite and sleeping. Because this is specific to your body it could be body dysmorphia? Honestly I don’t know, but don’t feel rejected if you don’t get a diagnosis and instead are referred to counselling. You won’t get turned away as you deserve help on this issue, it’s horrible when you hate how you look, it’s subjective because the way we look at ourselves in so much detail, spotting every curve and fault, when no one else even notices. Also there’s this thing called better help, it’s an app for 18/over, which offers professional counselling for 1/4 of the price. Its basically where you pick a counsellor (there are thousands - all have degrees) and you have them 24/7 to be able to talk to, video call, message or phone call. Obvs sometimes they won’t respond immediately because they have their own lives. Anyway that has helped me so maybe look into that if the waiting line is really long on nhs counselling?