Although I didn't have a tug flap I had terrible nerve pain from my mastectomy, reconstruction and node biopsy which was tunnled. I required somthing to assist with that, which was lyrica. I only required this for a few weeks and then weaned off. Tbe nerve pain settled.
Are you currently undergoing chemotherapy? The taxane class chemo can cause issues with nerve pain also.
Be aware that swelling if extreme can cause pins and needles as blood flow can be compromised. Maybe you do need to visit an Emergency Department to ensure its not an operational complication rather than normal healing.