I'm so sorry to hear of your struggles, it's horrible and tough and no woman sholud have to go through it. It's hard to find the strength to keep going and not lose hope but we have no other option so you need to keep going because the end is worth it!
I was told at 17 I would never have kids, saw every gynaecologist in the area and even outwith, several operations later and they're now saying there is a slim chance, only been trying a few months (since I got married) and this month I too convinced myself I was pregnant. The mind can be a cruel thing at times! I sobbed for hours when I took my period on Friday.. but your partner is right you can't lose hope and you can't give in so take a while to get your head around it all, relax, pamper yourself a little then try again.
I felt my husband didn't understand either, and it may sound a little pathetic but we have the "baby diary" now, where if I'm having a really bad day and can't get what's in my head out of it in a way he can understand (I tend to speak very quickly when stressed and my poor english husband can't keep up with my scottish tongue) I write it in the book. It's also proven we taken in the written word easier than spoken so as Mark reads it he can really appreciate all that I'm saying and then we can sit down and talk about it.
I'll be praying for you and partner, and hope that one day soon you get that long awaited good news!