My apologies Kjl! I'm also a she lol.
That's great that you made an appointment with a sub Dr. I'm not sure what the waiting period is when you're on patches, I think I read 36hrs, but please research that. I'm not sure.
There are things you can do to make the waiting period manageable. Taking Neurontin (gabapentin), Lyrica (Pregablin), some benzodiazipines (Xanax, valium, Klonopin, Temazepam), muscle relaxers can help. The waiting period is nothing compared to what you'd experience if you abruptly go off a a long term, high dose fentynal dependence.
I mentioned rehab due to your circumstances. I couldn't, in good conscience tell you to just tough it out. Not with the high dose, amount of time, having a heart issue, etc.
I never expected to have seizures and hallucinate when I detoxed. I didn't see that coming. I also lost my vision, and the complete use of my legs for about 3days. Also, never saw that coming either. As you can imagine, it was terrifying and traumatic. You're going to want and need medical advice and assistance.
Along with the above, stay hydrated, eat healthy, rest, etc. Physically and mentally prepare for the transition from patches to subs. Im on Subutex.
Mafioso gave great advice - stock up on Gatorade, Pedialyte, soups, pudding. You get the idea - easy to eat and prepare. Have your laundry done, straighten up, put everything you need either in a drawer right next to you, or on a tray.
You want everything stress-free, and ready. Maybe get some books you want to read, or movies you'd enjoy. Hard candy is also good to keep around. I like mints, they help my stomach. Also Coke. I usually drink Coke Zero, but when my stomach is sick, I drink regular Coke. It also helps with my stomach.
You're doing good! You have appointments scheduled. That's exactly what you needed. Well Done!