Suggest Treatment For Muscle Clotting In Penis

hi sir !! i am 28 years old,i have problem clotting of muscles on my penish,its starts when i contact with a girl and keep very hard sex,and after that i got clotting of some muscles on my penish at the corpus part and the part of root,only two places,!! i could not get any problem from it,but i am fearing that what is this?? its due to hard sexor due to other any infection,even i living with her since 1 year,and between this year i never met with another girls, suggest me please what to do??