Your best resource for looking into meds for depression would be a psychiatrist. When people have a garden variety short term depression their GP can be okay for this. However, when there are complex medical issues and potential side effects to consider it is best to see the specialists. A good, experienced psychiatrist will have dealt with movement disorders and anti-depressants before. People with Parkinson's and other issues that are co-commitant with their depression can end up with tardive dyskinesia from certain drugs though it is thankfully rare. Meds used for anxiety may actually help calm the nerves to a degree and help your sleep without contributing to twitching. The low dose of nortriptyline used for nerve pain is not enough to touch mood and as you said you are titrating down. Going ahead with a psych appointment would give you a safety net and established relationship if you do need to add something in for mood.

sending hugs,