Welcome to the Bipolar forum
I am sorry to hear about
your dx. I hope you are doing okay.
How long have you been on the Amitriptyline? Sometimes, we need to change meds if they're not working or get the dosage adjusted. Are you using any other meds for your carpal tunnel syndrome? Sometimes, meds do interact with each other so you have to take a note of all the meds you are using and be sure your doc is aware of them.
There are coping techniques you can use to help with the ups and downs. Distractions helps me. Sometimes, I would watch a movie, listen to music. You can also try going outdoors-just taking a walk. This helps.
Journaling helps as well. I write down my thoughts and feelings and it tends to make a feel a bit better. I also practice deep breathing. You can try these as well. They may help you