I’d request a Transvag ultrasound to see if you have a really think uterus lining or cysts. Normally a big bleed lasting long time is because your lining is so thick it’s very painful and very heavy prolonged bleeding making you feel terrible. Loss of blood low iron makes you feel super exhausted.
My own experience of course.
I had a dnc and an ablation and put on the pill. My bleeding all but ceased for many many yrs.
or you could have had a cyst rupture too. An ultrasound will help them see what’s going on, demand one from ur dr.

I had a similar situation, heavy bleeding for over 4 months along with pain and similar symptoms to you and all docs keep blowing me off saying it was normal etc, got bloods done turned out I had extremely low iron and had lost and insane amount of blood yet I still had to push more more tests as they were trying to discharge me. Definitely push for whatever you feel you need until you are comfortable, I also found having a great support system that could be there at appointments as an extra back up was helpful. My gynaecologist I have now found have been incredible. I live by pushing till I have a diagnosis and some answers or you might never get them with the health system we all have to deal with.

Go back to Ur doctor and tell them I want a scan done that what I did that how I new I had it and loads of test

Where are you based in the UK? You need to find a Endometriosis specialist. Best place to start is Nancys Nook on FB and get an appointment. May be worth finding the specialists private practice and booking the first appointment there. It will be a fee of between £100-200.but you will skips a 6-18 month waiting list.
After that if they want to operate they will refer you back to themselves on the NHS. So you wouldn't pay for the op. And because you've been seen, your op waiting list will be short.
x 🎗️💛

They don’t have one in the U.K where I live xx