I Have A Small Lump On The Left Side Of

I have a small lump on the left side of my meatus, I am circumsized and the lump is visibleif i look into my pee hole,I have masturbated a lot more frequently and i think that is what is causing this swelling, it hasn't hurt but it is swollen and making urination difficult because of it blocking the hole, I haven't had any other signs of an STD and i dont believe it is one. I think it might be and UTI but I'm not sure.