Help me out ladies

I'm in a new relationship and my partner And I had sex two nights ago for the first time. He is really on the bigger side size wise and it hurt so bad honestly and lasted so long ,even a second round a few hours later. Well I used the bathroom right after and had no issues. About 6 hours later when I got home I went to pee and it burned so bad also have a swollen vag. It is still swollen and still burns. Could this be a UTI or is this an STD ?