New boyfriend has a tiny penis! Help

I know this is pretty shallow but I just don't know what I'm suppose to do with it. It's like 4in. I'm 25 and only had sex with one other guy and he was like 7to 8in. We tried to have sex Lastnight and it just kept falling out it wasn't pleasurable at all. I really like him but how can I make sex enjoyable for both of us. Ideas for sex postions or anything. Please don't judge me.