Cut in foreskin and Arousal problem - Very Wooried

i recently had had protecetd sex and when i removed my condom i saw small cut in my foreskin with little blood. Subsequently i am unable to get aroused and even after lot of stimulation i get an errection it is very lose. I am getting very numb feeling . Can you let me know what the problem could be and should i be testing for HIV or any other STD

Thanks