Help help helppppp

So today, my man came over and we were getting it on and I felt him get hard, so I asked him if he had a condom. (This was our first time ever with each other) He said yes and attempted to put it on but he couldn’t. He got soft, and I didn’t want to make him feel bad so I told him it was okay. Eventually he went down on me and he was able to get hard again but when he would stop to try to put it in he would get soft again. Long story short we couldn’t fuck. Help ladies? Is it my fault? What can I do next time?