UTI Or Not?

Shorlty about my symptoms: I talked to my urologist, he believes that
I have a cystitis or bladder inflammation, but not sure if it is
intersitial. Two months ago I had a UTI. For various reasons I was
given 4 different antibiotics, twice because the lab result did not
(Bacterium and Micorobid) react to eColi bacteria, and once because I
got allergic to drugs (Cipro). They switched me to Ceftin, which
helped to kill the bacteria, but not the symptoms. I still have a
trace of blood in my urine, but lab results show no bacteria.

After 2 months I still have symptoms of cystitis (urgency to urinate
and burning after urination). My urinary stream looks like a fountain
or shower, my urination looks very heavy and I have sit on a toilet
for extra 3 minutes to make sure that I urinate all of the water
completely: in the first minute: it comes out almost fully, in the
second minute: it comes out in a smaller amount, and in the third
minute: it is still dripping. It is not really painful, but I feel a
lot of discomfort. I don't have a fever, or OBGYN problems, or kidney
problems, based on my recent lab results. The lab results show only
trace of blood in my urine.

I am wondering if you might help me to figure out what is wrong with me?