Sex help? My boyfriend doesn't sexually enjoy bottoming and it's frustrating!

[Darkkev02]

Hey everyone. I'm a 19 yo guy in a loving relationship with another 19 yo guy. We're both versatile and we both enjoy topping more than bottoming. Sometimes my boyfriend doesn't stay hard while I'm topping him and he says he still enjoys it and that he gets nervous it might hurt or something so he loses the boner. Today he told me the truth and that's when he's bottoming he doesn't feel that good inside his butt...it doesn't hurt or anything but it's not strong (knowing that we have a long foreplay). He says he's turned on and everything and that he loves the connection and the intemacy and that it feels good when i'm stroking him while topping but inside it just doesn't feel that strong. He also sometimes loses his boner because he's stressed and It gets really frustrating for me. I have a fairly average penis and I don't know if he needs a bigger one for his prostate to get more stimulated...Ive suggested the idea of seeing other guys but he said that he only loves me and he would only enjoy it emotionally more than physically with me and thats the most important part to him.
I don't know how to feel about all of this...I honestly love topping and I don't think I can let go of it but if hes not enjoying it as much as I was expecting then maybe I should stop?? He promised it's not my fault and that im a great top but i'm still worried. Help me!!