What really helps me stay positive is my "brushing mantra". Every time I brush my teeth, I think about two things I really love about TTC. I can't say the same thing twice for a week. It sounds incredibly silly but it worked for me. After about 12 months of trying to conceive I kinda slipped into a depression. Until then I had no idea what power a positive thought and desire can have on my state of mind until I made that switch. I've been feeling amazing, grateful and patient (Sorta. Not really. Well, kinda) ever since.
Things really took a turn for the better when I realized infertility (like everything else in life) is really what we make of it.
You can either make it hard on yourself, treat pregnant women like they're made of kryptonite and act like a jealouse moron at baby showers or you could just enjoy that damn baby shower, be happy for the girl and think "wow, cute cake. But I definitely want a cuter one for my baby shower!". Don't take the bitter route. Really. Don't. And don't think I don't know what you're going trough because I'm right there with you. I've been trough this Shes-pregnant-so-i-better-point-out-everything-that's-wrong-with-her-life phase. But you know where this gets you? Nowhere. It doesn't get you pregnant sooner and it definitely doesn't strenghten your bond with your pregnant friend. Infertility has a way of turning the most gentle, caring and kind women into a vicious bitch. Don't let it consume you.
I believe that if you put out negativity in the world, you get it back. That's really not what we need.
So what's the moral of this story you ask? Be nice! To (pregnant) people, to your body and to yourself.