He wasnt hard

Need advice. I just started dating this guy. Things started getting really heavy. So much in fact he made me cum twice. He is very sweet and im his first girlfriend and first at everything (we are almost 20). When i asked if he wanted me do pleasure him he couldnt get hard. I think this was performance anxiety or nerves. I dont know what to do. Was I not good enough or made him happy in that way? Was it just nerves. Im experienced and never had this problem. Please help.