What Causes Frequent Urination Along With Dizziness And Headaches?

Hi I'm a 22 year old female . Lately I've been very tired. Peeing all the time, feels like pressure. I've been dizzy,heachache. Past two days lower back has been killing me and side where spleen is hurts. I went to Dr and they tested for acute mono and uti but came back negative. Any suggestions on what it may be?