Vitamin C keeps breaking me out no matter what brand I try. what am I doing wrong? 31f

I've been trying to add a vitamin C serum to my routine for almost a year now and I'm about to give up. Every single one I've tried breaks me out within a week. I've gone through the Drunk Elephant C-Firma, the CeraVe vitamin C, and most recently the La Roche-Posay 10% pure vitamin C. All of them gave me small whiteheads on my cheeks that went away as soon as I stopped. I really want the PIH fading benefits because I have a ton of dark marks left over from old acne. My tret is helping with the texture but the dark spots are stubborn. I'm looking at the Timeless 20% Vitamin C + E Ferulic Acid next because the formula is different from what I've tried before and the ingredient list is shorter. I ran it through the ingredient checker on Thea and nothing came up as a trigger based on my past reactions which is a good sign since the last two serums both had things it had already flagged for me.

My routine right now: AM CeraVe foaming cleanser, CeraVe PM moisturizer, Biore UV watery essence SPF 50 PM cleanser, tret 0.025% (3times a week), CeraVe PM moisturizer Has anyone with oily acne prone skin actually found a vitamin C that didn't cause breakouts? I'm starting to wonder if my skin just can't handle vitamin C at all?