UTI, Urinary Tract Infection, or STD

So recently after I go pee by urethra burns and it feels as if I still need to pee, this has happened before and I just take an AZO pill and drink Cranberry juice and I'm good, but I have tried all that and it didn't work & the pain is becoming unbearable. I have only had 2 sexual partners but my boyfriend has had at least 6... we NEVER have sex without a condom tho. I also am having no vaginal symptoms.. evey thing down there is completely normal, my mom said I should go to the hospital after school so I am going to do so, I just wanted y'alls opinion on the situation.