This hurts so f****** bad!!!

So... When me and my SO have sex it's so damn painful like I feel like he is hitting my cervix and I literally almost pass out from the pain. It is not bad until he goes deep or from the back and he stands up on his knees. When he is crouched over me doing doggy style it feels good and there is little to no pain but when he stands up on his knees in it there is a sharp pain in the way back of my vagina and it is excruciating. I don't want to sound like a wimp or tell him it hurts bc i dont want to dull the experience and kill the vibe bc he gets really really into it , however I don't want to pass out while having sex either lol. What should I do? Has anyone heard of this before? Is there meds for it ? I am so lost at what to do guys help!! Fyi I am currently on the mirena and it has now expired almost a year ago I am getting an appointment to have it removed asap, could this be related to the mirena?