Needing advice with urgency

Looking some advice in regards to treatment. I’ve had ongoing bladder issues since I was 18 I’m 24 now. I was diagnosed with IC after cystoscopy and other tests. I am trying to manage to symptoms with urgency and frequency being my two biggest issues now. I’ve had ultrasounds which showed I am able to empty my bladder but I still am going to the toilet at least 4 times an hour have constant pressure of needing to urinante. I’ve tried a lot of treatments I was on solifenacin (gave me severe dry mouth) then mirabegron (initially worked then stopped) and finally trospium (ended up with retention). I’ve had bladder stretching and the bladder instillations however nothing has helped. My consultant recommended Botox however i need to self catherise to be able to receive this and I want to try all other options before going down this line as with any catheterisation I end up in agony for days after. My consultant is not starting me back on mirabegron along with amitriptyline. Has anyone been on amitriptyline I’m worried regarding side effects. And any other advice welcome in trying to manage my symptoms thank you