Painful urination

hi guys so I went to the dr yesterday for what I thought was a UTI. It was negative, but the dr gave me pyridum anyways to help with the painful urination. Today I woke up in severe pain and I’m running a fever. What should i do? I called the dr but they won’t give me an antibiotic bc I don’t have a uti but something is wrong 😭 I feel like my urethra is literally on fire