Vaginal tear after too much intercourse??!! HELP

I always get sore after having "too much" sex. And i'm always sore at the very bottom of my vaginal opening, according to this diagram I found, it's called my "posterior labial commissioner". And it gets SO freaking sore that sometimes I have to just tell my boyfriend that we have to stop bc it's hurting me.

My boyfriend lives a couple hours away so when he was here this weekend I ignored the pain and we had sex one more time because he was leaving the next morning (yesterday) and I miss him (y'all know how that goes🙄) and I've been SO sore since then. Like I can hardly pee or wipe without cringing because it burns. So I got a mirror and looked at it today and it looks like there's a cut??

I just want to know if this has ever happened to any of y'all before and what I should do to make it heal as quick as possible/how to avoid it happening again/etc.