Okay, I'm 21 years old. I had a girlfriend from the around 16-19 and was having great sex. I have really extreme anxiety, and panic attacks, hypochondria, etc. I haven't had sex since I got broken up with. *edit*. I've had chances but I just can't stay hard and maintain an erection no matter who attracted to them I am.*edit*. I always lose my erection though! I'm only 21.. And I don't know how to fix this

I think it would be a good idea to see a urologist to make sure
everything is working properly.

In young males, there are two main reasons for ED....
1) diabetes

2) a genetic condition you are born with called Klinefelter's syndrome (fragile X). This is more common than people realize and doctors often don't identify it quickly. Men with Klinefelter's can have various psychological struggles too. So I think you should have a testesterone test to see if you are low. Then comes a DNA test for it as a confirmation.

http://ghr.nlm.nih.gov/condition/klinefelter-syndrome

Your pineal cyst (which is more common in women) does occur in Klinefelter males.
http://emedicine.medscape.com/article/278174-overview

So I do think some diagnostic attention should be placed on this subject, if only to rule it out.

No, those symptoms don't sound like any of mine. I have normal size everything. Facial hair, body hair, normal sized private part although I do a a varicose veins on one testicle but I went to the urologist for that. I have no problem with masturbation or getting erected at at the initial "turn on". And had no problems at all with my long term girlfriend or before that. It's just recently over the past two years where it's like my anxiety and panic gets in the way before sex and I overthink things.. And lose my erection. I feel that it's all mental

I tend to agree with you that it may be all mental. Please take Lara's advice on your Neorologist? Thread, where you ask for places to speak to a Psychiatrist, although it may be a Psychologist you need.
Tell me, if you will as you are being so open as you get to know us, do you have thoughts or feelings of guilt when having - or after - sex? Guilt that something so nice shouldn't be happening to you?

Dave.

He forgot theres a 3rd and 4th issue. MASTURBATION, which its self stimulation, if you masturbate alot, your body will get used to that form of stimulation and that instead of actual sex, excessive masturbation can cause ED issue, it will desensitize your body to real sex.
If you watch porn as well, which people commonly do, it will also aggravate the ED issue, porn can overstimulate you as well.
all you have to do is stop mb/ and probably stop the "peep" shows if watch it. you will have to stop weeks to months, and see if your natural erections come back.