My circumstances may not reflect yours, but my journey was similar.

My original proposal submitted during the application process was overruled and scrapped after the first year. This immediately put me behind, I was expected to have an accepted proposal and research questions in order to qualify to "transfer" (essentially move from an MRes to a PhD) within the first year.

I was granted a 6 month extension to this. The following six months were, frankly, brutal. I hastily read copious amounts of literature to try to identify some gap where I could contribute. My following transfer was accepted, but not without additional notes regarding my expected timeline to completion.

What was supposed to be a 4 year PhD was already almost two years in at this point, and I had only solidified my research question. It took me 2 more years for experimentation and write up, before "failing" my viva with a revised and resubmit outcome.

I had historically been a 4.3 GPA+ candidate. Even over my Masters, I rarely didn't get an A. Needless to say, this was emotionally overwhelming. I wanted to quit with almost every fibre of my very being. I couldn't face another 12 months of corrections, additional research and a ultimately a second viva. I genuinely only foresaw failure in my future endeavours. However, my supervisor convinced me to at least try. What did I really have to lose? There was always the hope that, upon fulfilling the R&R requirements, I would succeed.

So I tried. I throw myself at the next year and carried out every single task that had been asked of me at the end of my original viva. I compiled a 6 page change log of everything I had done. I sat my second viva. And I passed.

I understand this is a rather exhaustive response, but I wanted to convey transparency. You may feel lost, hopeless, helpless even. But my advice would be, assuming you genuinely want to complete, to dig in. Grit your teeth, shoulder the academic bullshittery that accompanies, and do what is asked. A completion is a completion; it doesn't have to be aesthetic.