Weird sexual question....

I was thinking it was probably because he didn't wanna hurt me or the baby.Theres more to add to it...I am gonna put this in the best way possible, Sex turns him into an insane spider monkey.  So I thought it was just weird that he was quiet and calm, It was just strange.Normally there is alot more to it and this was just aggravating.  After it ended I ask him if something was bothering him and he said "no" that's all I get, Then I said "then how do you explain all that akward quietness" and he said "just not in the mood" then when I tried to cuddle with him like I do all the time he said "I'm to tired".   This is like torture!!  The day after that awful night, he went to kiss me before work and it was just like a peck. So heres our whole conversatio. I ask again if everything was all good and he said "I reallly don't know, Is something wrong"   and I said "not that I know of" so he said  "your acting weird, and I kinda think your trying to rape me or somthing"   So I laughed it off and he left..... I am soooo sorry I add alot of detail..  So thats my life right there feel free to add any opinion rude or nice whatever.

Yes,he is still taking it. I have been meaning to take him to the doctor to get a lower dose to wean him off of it.  My aunt was on depression medication for a few weeks and then found out it wasn't compatible with her other meds. So Then she just stopped taking it,a few days after that she commited suicide so I don't wanna do that without talking to a doctor. I really do think it could be a big part of it, I have been trying to talk to him but all he says is "yeah I'm fine".