Question about food supplement

I (afab 18) struggle a lot with eating because I personally find almost everything disgusting, and this includes many if not all vegetables and healthy food. I can't control it either and even if I try I get really nauseous and want to throw up. And everyone I know tells me I should eat better, but the few things that I like that sound healthy are often said to not be vegetables or not be enough (tomatoes, salad, mushrooms, peas...)

I've been getting many piercings lately and they're all saying I'll never heal because I don't eat correctly, and I understand and I know they're right, like my body is really weak and I get sick a lot, which probably originates from the fact I barely eat anything.

I know I can't force my body to eat what it doesn't like because I don't want to feel nauseous every meal and turn food into a chore, but it's getting to the point where even random scars from 8 months ago haven't finished healing.

I saw online that vitamin C can help with immunity and healing and stuff, and that's what's found in most vegetables, and I was wondering if I should go see a doctor to ask for food supplements or if it was useless.

As I'm a student with very little money, I can't really afford to go to the doctor just to ask (because in the outcome where they say no that'd be like a "waste")

(I live in France and it's still a country where the appointment would be reimbursed later, but that would still be a moment where I don't have the money I might need).

Thank you for your time and I hope I was as clear as I could.