As you have not had a prior diagnosis of depression, NICE guidance is that HRT is used for psychological issues.
Regarding thickened lining - I had a scan due to experiencing frequent urination.
The weeing more often was also most likely linked to loss of estrogen. You can read up about this online (it's now called 'genitourinary syndrome - GUS') The bladder lining is very sensitive to estrogen loss.
Did anyone mention this to you? The treatment is vaginal estrogen (cream or a tiny pessary.) It is not classed as HRT and there is no absorption into the body.
but I suspect that I now experience thicker linings due to extended cycles
Yes. If you are going months with no period the lining builds up.
When I tried HRT (prior to the scan). I had a horredous period - flooding, clotting never seen anything like.
You said that some patches were falling off. It's possible that the patch didn't give you the amount of progestogen needed to keep the lining under control . OR that you had a lot of build up in the lining already and it came away with the HRT withdrawal bleed.
I know it all sounds scary and a lot to deal with, but it's probably not that complicated to sort it out. Ideally, what you need is an estrogen-only HRT for a few weeks to see if that sorts out your mood (getting the estrogen dose right) then adding in a progestin to control the lining.
My own experience from a specialist was 10 weeks of estrogen only, followed by 10 days of progestin. NICE has now updated it's meno guidance to say that all women in peri can have this regime which can work really well for women with progesterone intolerance.
Your GP could offer you this. You don't need to see a specialist, but if you do, the BMS has a list on their website. It's not conclusive- there will be others who aren't on that list. thebms.org.uk/find-a-menopause-specialist/