Acne?

I’ve had acne since I was 9. I’m 21 now, and I’ve noticed that there are some fluctuations through the month so it might be hormonal, but I never have completely clear skin no matter what time of month it is. It’s actually been much worse than this when I was in my early teens. I’ve used many face washes and nothing has made a difference. I really can’t afford to go to the doctor or try any expensive products. My forehead is completely clear, it’s mostly just my cheeks. My skin is very congested. Almost every single pore is clogged and there are large underground bumps. Does anyone have any idea of what might cause this kind of acne?