I had a year of herceptin, 9 months on its own, with no side effects. So it may be a lingering chemo reaction. It's also possible that everything is getting you a bit down. I too have peripheral neuropathy and lymphoedema, the latter was somewhat of a pain until I got the right sleeve for me, not hot and not uncomfortable. Unfortunately you may have to try a few to get one that feels good and also works (which is a cost).
The neuropathy should improve but it can be slow. But if the nauseous feeling persists talk to your oncologist or oncology nurse. Best wishes.