1 year, 1 huge penis, still hurts

I've been with my SO for over a year. At first, sex was nearly impossible because he is well endowed (IM TALKING Long and girth-y). I thought after the first few months I would be used to it, but that is just not the case! After almost 8 months of passionate love making, I still experience pain and tearing 1/3 times. It's not that I'm not wet enough or that he's being too rough. I guess I'm looking to see if anyone else has experienced this or if this is normal?