I stopped masturbating, but now having uncontrollable erections

pls i used to masturbate but i have stop But when my girl friend come to me anything I erect uncontrollably,even tho we not having sex at that time not even cuddling but i erect and some non coloured sticky fluid comes out from my penis and spoil my self even when we having a walk in public I dont know whats wrong with me Can somebody help me with anything i can do to do away with this Or any medications to prevent this Bcx am disgracing my self pls