soft erection

I have recently have not been getting a throbbing hard erection like I am used to.
It gets hard enough to stand up and have sex but no where near like it usually does. I had taken some stamina rx pills a few times to increase stamina and wondered if they were contributing to the problem. Also my girlfriend had bent my penis backwards from the base and for the next couple of weeks it wouldn't get fully hard at the base and would lay there half hard. Its getting full there now but I still am not performing like normal. It also takes longer to get my second wind now and does not stay hard when doing so all the time. I tried taking the pills again and they keep me erect and give me a second and third erection right
away but it still does not get like it normally would.