Penis problems jelquing accident masterbation problems?

ermm im 15 i attempted hanging with my penis. put a towel over it erected lifted the towel. then few weeks later just found myself not wanting to masterbate. i thought i was just havin a mental thing but when i tried to masterbate my penis had a thick blue vein up the side of it and a green one on the top. also i cant get a full erection it can be bent easily. if i stop for a minute i lose erection. i can still ejaculate but when i do my penis still isnt the hardest it can be.i dont really want to see a doctor if i dont need to. can anyone explain what ive done and what i need to do to treat it please thanks.