Me and my partner are having trouble with BDSM

So the other day I told my S/O I wanted to try forced and BDSM stuff in general we agreed that either could initiate and that our safe/stop word would be Banana.

Well tonight he gives me a lotion Massage (Kinda Obvious he wanted sex)

Earlier we had bought a kit of toys well he rubs me for 30minutes and then tells me to close my eyes he starts hitting me with these tassels it felt good and he got up and started trying to do stuff I'd said no get off but he thought it was part of my fantasy well he gets off I'm mad he believes I'm role playing it so hes pretending to argue with (I guess) hes joking around during and then he grabs me by the neck but was aiming for my chin. But he grabbed a little bit of my throat with my Jaw and it hurt. Well I get real mad he realized I was serious.

Well he actually cried because he really hurt me, and said he didn't stop because I didnt use the word we had agreed on to stop.

I'm curious if anyone can give us some advice on ways to make a forced fantasy work and just on BDSM stuff in general