OR nurse with difficult erection

Patient: I’m having a hard time getting an erection. I’ve been with my current girlfriend for about a year and have never had this problem until recently.I started a new job back in April and have been tired a lot. I work in the OR and have to do multiple foley insertions daily. Can being constantly tired and high exposure to vaginas cause difficult achieving an erection?I exercise and eat healthy. And I’m 28 years of age