Been on prescription pills for 4 years , need insight

I'm a mom of three, pregnant with my fourth. I have an insane amount of Problemss with my health. I have thyroid disease and partial removal of my thereof along with a tumor. I have severe nerve damage from the surgery, severe migraines that often hospitilize me severe tmj and fibromyalgia along with endometriosis. I have been on like 18 prescriptions all to combat my symptoms of pain, wasn't planning on pregnancy and found out a few weeks ago that I am. I'm trying to wean off of my oxycodone . It's killing me. The pain I endure daily is tremendous. It makes it hard to move, be active, love and be a better mom. I've seen pain specialist and this is what they agree is the best treatment. I don't know how I can possibly get through the pain without my pain meds. Been on them for over 4 years. I'm terrified. I'm afraid once they find out I'm pregnant I'll suffer and my kids will suffer. I'm at a loss. The pain gets so bad that I usually get hospitalized. I wish I didn't have these stupid diseases. Anyone have any helpful input?