OP here:
Two texts from my friend already today. I'm going to have to be honest and say something, aren't I?

I realize I wasn't clear in my original post. My friend does know all the details of my situation, including all of the unfortunate back-story. (I had life-threatening post-partum complications after DD's birth, and she came to visit me in the ICU almost every day. As I said....she's a good friend.) She does know how devastated I am, but she couldn't know that I still cry at least once a day over this. I have avoided mentioning my circumstances or any of this for a while now, for two reasons: 1. I just didn't want to rain on her parade, or blight her happiness in any way by bringing up my sadness, and 2. The last few times she's brought the subject up, she's gushed, "Ooh! I just heard about this terrific adoption agency you might want to look into!" She's trying to help. But that's just not the sort of thing I need to discuss right now.
Thank you all for saying that I'm not a special snowflake. I'd forgotten, but none of this was an issue when my nephew was born, and I'd expected that event to really lay me low (my SIL and I were due within days of each other.) I was really quite okay....however, my SIL is the soul of tact - rather different from my friend. My friend (and in her defense, she was like this with her other pregnancies as well) had to include the fact that she is pregnant with almost every sentence that she utters, bless her heart.

As in:
Me: Hey, would you like a piece of chocolate?
Her: Well, of course! I'm pregnant, after all!
Thank you all for the wording that you've provided.... I will definitely use it. And thank you again for your support. I promise that I didn't come to an etiquette board looking for emotional support, but how wonderful to find it! A long time ago, I remember reading something on this board to the effect of "the ability to get pregnant isn't like winning a prize....." something like that. Babies are going to continue to get born - just not to me - and it's very important to me that no one feels the need to "tiptoe" around me because of that. It's difficult now, but I don't want that always to be the case. (Side note: I am taking steps to come to terms with all of this - such as joining a gym! - so that I can move forward in a mentally and emotionally healthy way.)