Rough sex gone bad

Hello everyone, an incident happened yesterday and i really need some feedback on it. So my boyfriend and i were having sex, and he was choking me alittle, which he does occasionally and i don’t mind but keep in mind he is a pretty strong guy and quite powerful. We’ve had discussions before about him being too forceful or overbearing. So he’s choking me and it’s getting rougher and tighter and all of a sudden i black out for a few seconds, so i freak out and tell him which he kinda brushes it off and says I’m sorry i didn’t mean too and keeps on with the sex. He is a lot more kinkier and rough then i am. So this morning i wake up and i have a huge bruise on my arm, my chest and pretty much my whole neck. I know he didn’t purposely mean to choke me that hard but I’m kinda scared of what this could lead too, am i over reacting or over thinking??? Thanks in advance!!!