ERectile dysfunction in young men with the same partner

Patient: I am a 25 year old female and the last two men I have dated have both had erectile dysfunction. Both men were in their late twenties and active healthy people who were not involved with drugs or alcohol abuse. I also consider myself to be an attractive person. My last boyfriend and I dated for about five months and we were never able to have a normal sexual relationship. My current boyfriend and I have dated for about four months and I am ready to have sex but he is not able to achieve an erection except for in the morning. Both men have said it was due to nerves but when I looked it up it seems that it is very rare among people in the 20s. Is this just bad luck or is it more likely something to do with me?