I have been seeing a new woman lately, and while last week I had no problem getting hard numerous times for sex, I can't seem to get a full erection this week. At first I thought it must just be nerves, but now I've noticed that even when masturbating I can't get a full erection, though I can still come. It's kind of freakin me out! I don't drink much or do drugs. I have been eating pretty healthy. I am a vegetarian. The only thing I can think of that has changed recently is that I have started running fairly regularly. Does anyone know what could be causing this? Do I need to go to a doctor? I have had this problem in the past for maybe a day or two but only with a women, never when masturbating. Is it possible that I am still nervous about it even when masturbating and that's causing the problem? Any advice would be greatly appreciated! Thanks.