Starting my treatment journey

Hi everyone.

I'm new to this, so please bear with me.

My fiancé and I have been ttc for about 18 months, without success. I was diagnosed with endometriosis earlier last year, and had a surgery for it last summer but it didn't help. We were referred to an infertility clinic in October this year (why are they always in the same place as maternity units?!). My fiancé has had all of his tests, and they came back great. I've had my bloods done (fine), an internal/external ultrasound which found evidence of endo and adenomyosis, and a Hysterosalpingogram which came back clear. We've got an appointment at the clinic on Monday to discuss treatment options. 

My friend is fostering an adorable little girl, and we look after her sometimes to give my friend a break. I love looking after her, because it means I get to be a mum for an afternoon, but I feel so down when we have to hand her back. The house feels so empty and quiet. To be honest, I've never been particularly hung up on whether or not the child I raise is mine biologically, and we'd adopt her in an instant if we could, but that will never happen because we're years away from being able to apply. It's going to be devastating when she returns to her biological parents or is adopted. To make it worse, my friend keeps making comments about how good I am with the little girl and when are we going to try for our own family. I'm close to her, but not enough to want to tell her what we're going through.

I know loads of women who are pregnant at the moment, and I dread seeing them/hearing about them. I've already told my fiancé if we're lucky, he's got to make sure I don't turn into one of those insensitive women who moans constantly about how hard it is being pregnant or talks about nothing but babies. It seems to be all I hear from my pregnant friends/colleagues, even those who do know about our problems.

Sorry for the long post. I don't have anyone else to talk to about this, other than my fiancé, and with the clinic appointment coming up it's all weighing on my mind at the moment.