My Penis Nerve Got Weak Itseems. I Am Unable To

My penis nerve got weak itseems. I am unable to satisfy my girlfriend in bed. She's getting anger on me because of this. She's avoiding me. If she calls me to the bed. Suddenly i am getting nervous and shivering also. And when i insert my penis into her. Sperms are coming out wid in few seconds. And i am unable to go for the second round also. Please help me. Is this curable? Thanks in advance.