Sadly, there are lots of us with 2ndary infertility. I tried for 3 years (6 stimulated IVFs and 2 NCIVFs) and just did a DE transfer. My first was so easy, but we were just really lucky b/c we have severe MF and now crappy egg quality. I knew pretty quickly that I was comfortable with having a child using a DE, but I will say that it took a significant amount of time to feel comfortable with the details of the process (finding the right donor, procedural ethics - we opted for a known donor as a result). I have a friend who is also dealing with secondary. She decided to quit trying after having a bunch of miscarriages. I also know someone who did DE about 13 years ago, and 3 others currently struggling with IF, 1 of whom has secondary IF. I'm pretty open (other than with work people), but certainly don't announce it. However, I don't think I'd know of any of these people, other than maybe my close friend, if they didn't know about me first.
I'm not sure I could keep going after a certain point as you are. I'd be hopeful every month and then, even though I'd be expecting it not to work out, I'd still be a little disappointed. I already know that takes its toll on me. I'd need to have the mindset that I was done to really feel like I could move on and be free from the worry and disappointment. But, I'm not sure I'll ever not feel a little something at certain times when I think about how this didn't go perfectly. It'll just be less as time goes by. (I think I can be happy and love a child and celebrate his/her origins, but still recall the feelings of such a difficult journey).