Endometrium 26-29mm

Hello.

i was recently admitted to hospital after months of never ending bleeding, passing large clots and awful abdominal pain.

they did a scan where it showed the lining of my womb to be between 26mm and 29mm. 

Apparently this is very rare in younger people - I'm almost 23.

I had a biopsy done however they struggled to get it out of the tube as it was so thick so I need another one on Friday.

ANYONE who has been told they have a thick linining can you please tell me what the results of this was? 
good or bad. I want to prepare my mind. Nobody I know has went through anything similar.

edited to add; I'm already on the coil and the pill