Possible Cystitis

[Pyqt]

28 year old male have been experiencing the following symptoms over the past 1.5 years.
burning while urination
burning sensation in bladder area
constipation and thick foul smelly stool
cracked corners of mouth
clammy and warm feel of penis
rectal itching

This all started about 3-5 days after I had unprotected sex with a woman from Eastern Europe. I have been tested negative for all the typical STDs and parasites (HIV, herpes, gonorrhea, chlamydia, syphilis, hepatitis, mycoplasma, giardia, HPV/warts, etc). All urinalysis and stools tests came back negative as well. I have seen a urologist and proctologist which have diagnosed me with proctitis and interstitial cystitis since they can't seem to find the cause of my symptoms. Both doctors think my sexual episode is merely a coincidence to all of these symptoms occurring even though I had been 100% healthy prior to this episode and have never experienced the symptoms above.

I was first prescribed moxifloxacin and my bladder pain seemed to go away for about a week and it came back. Accepted the doctors diagnosis that I had intersitial cystitis but then about 3 months later I starting having really bad gas and diarrhea. After some research, I possibly thought it might be a parasitic infection so I went to a proctologist and was prescribed Metronidazole and doxycycline. My bowel movements started to become normal and all the urination pain, clammy genital feeling, and constipation/diarrhea vanished. Problem is that all symptoms returned about a month later. I then went back to the doctor and he said to try the same medications. First couple of days seemed to help my symptoms then I regressed into constipation, groin pain and warm/clammy feeling.

I recently tested negative for candida which I thought was the culprit. Thinking about going to a infectious disease doctor to see if they have a different take on my situation.

I've seen people post about similar chronic bladder issues but not much like the issues I have experienced.

Any help would be much appreciated.