The discontinuation of birth control can resilt in a hormonal
imbalance which could have easily resulted in the symptoms you are experiencing. Your symptoms could be related to a hormonal imbalance cause by endonteriosis as well, but it is morr likely to be due to the discontinuation of birth control.
If you were also diagnosied with interstitial cystiyis, why were you not put on a course of antibiotics immediately? I am unaware of the system that is followed there, but in my country this would account to medical negligence.
Please drink plenty of water in the meantime abstain from sexual intercourse and also try to add cranberry juice to your regimen while you are waiting for an appointment with your urologist
to get through.
Hope this helps.