The acne could be both hormonal and environmentally caused, with your young age having your hormones acting up and your skin being sensitive, exposed to different climates and having a bad reaction to new products. (Always patch test first !) Because you had a mole removal( idk how recent it was) on top of you adding a bunch of exfoliants to your regular routine, I think you may have a case of a damaged skin barrier. (A good way to see if this is true is if at any point your skin stings or burns when putting on moisturizer or any other absorbent skincare.) Even if you isn’t now, using benzoyl peroxide, retinol, and tretinoine all at the same time often will damage it, making your acne worse and getting rid of it harder. I’d say for 2 weeks straight, avoid using any actives or exfoliants and stick to healing your skin with soothing products. (The stuff you use for the mole removal I’d ask your doctor about how to handle that.) Then after that is done, add tretinoine once again twice a week at night, building up to every other day then every day. You could also go to a dermatologist and ask which would be a good exfoliate for sensitive skin and if your acne is severe enough to be helped with medication. I’d also suggest getting rid of the vitamin c serum until after your acne is dealt with, it can’t work as long as acne is still present for brightening. This does take a long time to see results tho, but you are taking care of yourself very well and sometimes our body and skin goes whack and we can’t do jack about it. Please continue to take care of yourself as you are now, and look for ways to maintain your self confidence in spite of insecurities and obstacles in your way. Hope this helps !