Thanks everyone for your prompt replies - it's nice to see people helping people even in this cut-throat world.

So after a full day of ripping my hair out it turns out it was related to my time on my comp. It was 10 mins off and I hadn't noticed. I changed the time to reflect the accurate time, deleted everything in my appdata folder and resynced the chain. Thank f, but it works now. Again, it's much appreciated to have community members AND the dev reach out in such a short amount of time. MN here I come!