Endometriosis

So I was diagnosed with endo about three months ago. I am 20 years old and my bf and I have been ttc for 8 months now. I then found something in my underwear which I wasn't sure what it was but thought I'd maybe mc again. I feel so sad and hopeless that nothing seems to be happening for us. I also have kidney damage which I've had since I was born which resulted in high blood pressure. Has anyone else been in a similar situation? Or have any advice?

The doctors have said there is very little they can do for the endo, but I get my period normally every month.

Can anyone identify what may have been in my underwear? I'm very scared and confused 😞