I just read your post and while it may be a bit late I am going to write it anyway. Take control let him know whos boss if he wants you to grind and he dont like the way you do it. Tell him to shut up as its what he wanted and if he explained stuff to you a bit more it might be a bit more pleasureable for the both of ya.
As for getting angry wot an ass. He obviously doesnt really care about you or he would care how this sort of treatment makes you feel. It also sounds like because of the way he is treating you and making you upset he kinda gets off on this submissive stuff whether you realise it or not.
And lastly if you dont want to go down on him then dont, we all know it dont have the greatest taste but if you are doing it to make him happy you shouldnt be doing it and if he is cumming in your mouth and u dont want him to when you think he is about to finish or is close take him out of your mouth and finish him by hand if he trys to put himself back in your mouth you can do one of two things.
(a) just pull away and leave him hanging or
(b) many years ago I was seeing this guy who was not good for me but thats another story anyway his then girlfriend didnt want him to come in her mouth but he did this one day and she took it and didnt let him know that she 'hadnt disposed of it' and then she kissed him and spat it into his mouth. All he could do was swallow his own semen.
While this story may seem gross and all the guys out there are going he had choices well let me tell you so do you, I betcha he wont like it so y should you put up with it.
Let me know how you go
from someone who cant wait to have a jelly bean all of their own