I'm 28, 6ft. 2inches, 248 pounds, and high blood pressure runs in my family on both sides. A few months ago when my girlfriend and I started having sex, everything was fine. Now these last 5 months, I can no gain a full erection, nor keep what little erection I do get. I'm feeling horrible about my performance, and I know she is not satisfied like the past... What is going on? Is this normal? Can it be fixed?