Recent taper of Nori- Insomnia

So, I have been having some recent dysautonomia and after a heart monitor, ecg, etc. I decided to come down and potentially off Nortriptyline after almost 7 years. I went from 75mgs to 50mgs daily with no issue, then recently dropped to 25 mg over past 3 weeks. It wasn’t until I got a brand new bottle of 25 mg capsules (same manufacturer as usual, same dosage) this week that I started getting dizzy and amped up immediately after taking it and I have barely slept in the past 4 nights. Not sure what it could be, is it the new bottle of meds, is it that taper withdrawal caught up to me, is it hormones (perimenopause) is it coincidence? Whatever it is I need to figure out because I need some sleep. I’m considering going back up to 50mgs or should I ride it out for a little longer to see if it settles down?