20 Y/O and can't get a full erection

Hello, I'm 20 and ever since the age 13 I have been able to sustain a full erection. I don't drink or smoke or use any drugs. It get hard and only goes up to 45 degrees as opposed to 90 degrees. If I lie down on my back it swings to whichever direction gravity pulls it as opposed to standing firm and erect.

I'm really concerned and it has halted me from having sex even with the numerous chances given. I feel like something could be blocking a full blood flow therefore the base cannot hold it up. The penis is sort of heavy at the tip and end and light at the base, so it gets hard but hangs.

Please help, I'm really missing out on potentially mind blowing sex.

[metropolis]

Go see a doctor. Only a doctor (urologist) can determine the cause of your problem and prescribe the right treatment.

[rajpali]

actully i want to make my penis larger i am very much warried about this because it is very small and my girlfriend is not getting satisfid with it so plz  help me out.