Hello -
i had the same problems as you when I was 22. I am now 29.
Like you, the doctors said it was all in my head etc etc. But that would not stop me from getting further tests.
Heres all the test ive had done.
1st - they did a scan to measure blood flow into the penis. To do this they injected something to give me an erect penis (after 2 attempts ouch). Then kind of used an ultra sound thing.
The urologists said I had leaks in my penis. One option was to "sew" or block these leaks so blood would not flow out. I opted out of this option.
2nd test - I stayed in a special clinic over night for 3 nights. The technician put a measure device around the penis to measure blood flow when I was sleeping. The results proved that not enough blood was going to the tip of my penis. Again the doctor said relax relax. . By this time I was totally fed up. Ive used viagra but, really dont like the bad vision and stuffy nose effects I get.
Now, a few years on, I havent had any tests. . But am looking for an alternative pill to viagra.