Unable to get off of medication.

Hi doctors! I was prescribed a medication (nortriptyline 25mg) almost 2 years ago for about 6-7 months but I continued taking it beyond this duration(I still take it) because it really helps. I was also asked to complement this with CBT with a therapist and I tried (with 3 different therapists) but that wasn't very useful at all. I'm having a super hard time finding a qualified therapist who can actually provide me with realistic solutions, so far I've been unsuccessful and the pandemic isn't helping either. I want to know what are the risks of taking nortriptyline for prolonged periods of time and how safe it is for me to do so. I have tried getting off of it but badly suffered from withdrawal symptoms that interfere with my daily life. Without it, I can't sleep well, feel tired and grumpy all the time, can't eat /feel nauseous looking at food (especially oily/fried) and just feel angry and jittery all the time without it. The medication helps me greatly. Thanks!