How do I as a younger woman begin to learn how to practice kink related stuff safely?

Hi, I don't wanna disclose my age. I've been dating my bf for a while now, like 8 months. We've had sex for that whole period of time and as time goes on weve like started to explore. we'll like watch porn and then do that kink or like spin a wheel of kinks and try it etc, and we are into a lot of stuff.

However I've been getting hurt a lot :( for example last night he choked me and i pretty much blacked out, it was rly scary 😭 so I'm looking for like a place or smth or smth I can read or just ANYTHING so I can learn how to do this safely without actually getting hurt