hi my name is Monny.I noticed erectile dysfunction from last 4 to 6 weeks, I am living with same girlfriend about three years and never had this problem before,One day morning I had a loads of foreplay with my girl friend , then I went to toilet before doing sex with her, in the toilet I thought I am almost nearly calming so I masturbated as I want to enjoy more I thought may be I calm before her so she will not be happy I thought after masterbating I will take longer time to calm again and I will enjoy more when I back to my bed in few minutes after masterbating I tried with my girlfriend but no erection in my pennis, I never did like this before and never had this problem before,I relaxed for couple of days and tried again but same poor result, after few days tried again but erection for few seconds but looks tired and my mind always thinking I will lose erection so what happen I lost my erection again and again, afterward I went to GP he prescribed me Viagra the Irish brand dont know exact name but I think it was similar to Viagra but different brand name, it was alright I took 4 tablet of 50mg over four times before sex,Now my girlfriend is away from me for couple of months so I didn t tried at all, but I have no erection or sometime just for few seconds and always feeling my pennis is tired,I am working in night shift from last few years 4 to 5 nights in a week so a little less sleep over past few years.Please can you answer me these questions:1. Is that the reason I am tired enough?2. Is my thinking means my mind goes off during sex so I lose erection?3. Tensions or less sleep?4. Can it be fixed?Thank you in advance for your help.