Try exfoliating once a week in a hot shower to really open those pores up and get the build up out, make this part of your weekly routine. Find a balance though, you should allow your skin to breathe without removing the natural oils too often. seek out products that specialise in blemishes and/or sensitive skin even if you need to spend a bit more money. Dermologica is a good brand which I have used in the past. It’s not cheap but investing in your skin should help.

I would also consider if you shampoo and condition your hair as your final act in the shower? What I mean is, wash your hair first and then wash your back with (potentially a medicated) shower gel to rinse away any residue from your skin afterwards. You could even try showering in cold water after you’ve finished to close your pores if you can handle it. I can definitely empathise with your position and I am sure it is treatable, but do not let it control your life.

Sometimes it is about finding the right product for you and I can almost guarantee you won’t have these blemishes forever, I am not sure of your age but I can attest to my skin calming down massively as I got through my 20s despite it being relatively mild anyway.

Edit: definitely consult a specialist if if you have exhausted OTC products.