I need denistry but I cannot afford private or find an NHS dentist, what can I do?

I’m 27 and from Ukraine; I’m covered by the NHS, and I’ve been looking through the thread on Reddit about dentists… it seems almost impossible. Lots of people are trying to get help, but there simply isn’t any, or you’re put on a waiting list just to get registered for years on end.
The reason I’ve mentioned my age and where I’m from is that I can’t afford to go to a private practice, as I’m literally here because of the war in my country. Because of the depression I’ve developed as a result of the events in my country and my forced emigration, my teeth are in a terrible state, and after I was prescribed iron (liquid), they started turning black and nobody told me I had to drink the liquid very carefully through a straw. Now I’m here and absolutely shocked.
I don’t know what to do, given that things are getting worse and worse every day.
What would you do in my situation?
I really needed help about five years ago, but when I asked my GP, they didn’t help me at all.
I live in York.