Questions/concerns about stretch marks. Help?

Sorry not sure what category to post this in.

I have questions/concerns about my stretch marks. I have never been pregnant, but have been chubby all my life, nothing drastic though.

I have stretch marks literally all over about 70-75% of my body. I have a huge set of them on my back, I have them on my inner thighs, I have them on my stomach and hips, and behind my knees. I have never went through a drastic weight change, but it seems like these stretch marks will just randomly appear whenever they want.

I don't want to sound superficial, but they bother me so much, they really do. I wouldn't mind if I had a few, I know they are normal, but I have SO many. I live in Florida, and I don't even want to go to the beach because I'm ashamed of these scars. Why is my skin so bad?

I have been to the doctor and 3 different dermatologists. They don't understand why I have so many and so severe stretch marks. Cushings, diabetes, pcos, other skin conditions, etc have all been ruled out from testing. It also does not seem to be genetic, as my mother and grandmother both have not had any.

I'm really young, I started developing stretch marks during puberty, around 13 y/o, and have consistently been developing more and more. Could there be something wrong? I don't feel like this is normal.

I admit I've never really ate healthy, I don't eat junk, but I don't eat vegetables, I skip breakfast a lot, things like that. could they be caused by poor/ or lack of nutrition? That's the only thing I can think of.

I found out there is nothing you can necessarily do to get rid of them, which sucks. So at this point, I'm not sure what to do. Does anyone have any advice for me?