Hi Ellie
Aww I know you must be worried but it's a normal thing to do a hysteroscopy to check for fibroids and polyps which might not be showing up on your ultrasound, it's good news that it all looks fine. The thickened womb lining is apparently not as terrifying as if you Google it....I don't know what yours is but 4 years ago mine was slightly thickened at about 12mm and it is now around 23mm and the GP has only just send me to the Gynae who is going to do hysteroscopy to check me out. Like you I have been having problems for the last 4 years, sometimes I bleed, sometimes I flood, sometimes I spot and sometimes I think I am going to bleed to death. Other than my iron taking a battering I am still here despite bleeding since early December. I bleed through tranexamic acid, cerazette, and at 44 my bloods say I am not yet perimenopausal although my body begs to differ! If you read more on here lots of women are in a similar situation to us and there are even some lovely posts from women who have made it to the other side of it all.
Please try not to stress and keep us posted xxxx