Bladder Pressure, light burning, freq. urination

Hi there, I have been dealing with this issue for almost 2 months now. I am 32 years old, female, I hardly ever get sick and I am in generally good health. About 2 months ago I started feeling this ache or pressure in my lower stomach only on the left side . It feels like it is in my bladder. I went to the doctor and she told me I had a UTI, she put me on Bactrim for 10 days. The freq. urination and the burning went away but the pain in my bladder didn't. I waited about 2 weeks and then the burning started up again so I went back to the doctor . She then gave me medicine for bacterial Vaginosis and did a pap smear . The medicine was a gel metronidazole. Well after I ended that medicine I was starting to feel alittle better but 3 days after that my freq. urination and ache in my bladder came back. That day my doctor called and said they had my panel back and I tested postitive for ureaplasma and she put me on a zpack 1 day dose. Well I took the zpack yesterday and I don't feel any better , last night I urinated 5 times in an hour and my bladder is so sore today. Like I said the achy feeling is only on my left side of my stomach and on that side is so bloated and when I bend over I can feel the pulling in my bladder. My bladder feels alittle better after I pee but sometimes I can feel a shooting pain when my bladder is almost empty. I don't understand how my urine is clean but I feel like I have some kind of infection. Any help would be greatly appreciated. Oh and anything w/ caffeine sets me off so bad so I have been staying away from pop and coffee and tea. Even cranberry juice hurts my bladder also, maybe too much acid? Thanks !