I've made a huge mistake (tax-related)

Hello

From 2020-2023 I was working as a contractor. Did I put money aside for GST etc? Yes. Did I then use that money when we hit a hard financial patch and needed to cover the mortgage? Also unfortunately yes.

Have I done a tax return at all for any year in that period? That one is a no, unfortunately. Turns out I'd rather just have the stress of the IRD hanging over my head, because unfortunately I am quite stupid.

I now want to get it all sorted. I just want to know what I owe, and figure out how to pay (am selling house, that should cover it).

Anyone been in a similar situation and know who I should ask to do the numbers bit? Xero? Any particular accountant? Any recommendations welcome.

PS I would like to be able to claim some expenses if possible but I only have bank transactions not receipts. Am I screwed?

Thank you for any advice!