Problems with UTI and how to treat symptoms.

Patient: Hello , My name is Anna. I’m 17 and have recently been to the doctor about a UTI. They have confirmed that I had one then sent me home with antibiotics two days ago. A bit before I went to the doctor I had been feeling feverish , nauseated and I had abdominal cramping. I didn’t have a fever when the doctor saw me , but now I do and had to be sent home today from school. Today my nausea had increased greatly and I also ended up with a bit of diarrhea. I am concerned and a bit worried as to what is truly wrong with me. Has my UTI gotten worse or do I have something else?I also have lower back pain and aches in my legs. I just wanted to know what could be wrong , how urgent it is and what I should do to treat myself at home . Thank you

Symptoms: Urinating frequently , Nausea , Lower abdominal and back pains, Legs pain, diarrhea, No appetite , Fever , Chills , Burning and pressure when urinating ( But that symptom has already subsided)