I'm scared

3 days go I had sex with a condom the next day i felt sore and a bit swollen (he was big I wasn't properly prepared) I started to feel really itchy and had a little bit clumpy white discharge odorless the next day I had fishy discharge thats a bit dark cloudy pee no itching but the smell foul could I have still caught a STI or is it a UTI ? I'm scared and embraced to go to the doctor I know i have to go but I'd like to know what I might be dealing with to mentally prepare