Hi @dhramsey - welcome to Connect. I can't imagine how awful it would be to deal with a new daily persistent headache for as long as you have. I hope you and other members find some answers that help. I did a search using Google Scholar (https://scholar.google.com/) and found a few articles that may provide some useful information:

New Daily Persistent Headache and OnabotulinumtoxinA Therapy
-- https://journals.lww.com/clinicalneuropharm/Abstract/2019/01000/New_Daily_Persistent_Headache_and.1.aspx

An RCVS Spectrum Disorder? New Daily Persistent Headache Starting as a Single Thunderclap Headache (3 New Cases)
-- https://onlinelibrary.wiley.com/doi/abs/10.1111/head.13495