Does it ever go away?

That gut-punch feeling when you hear that someone you know is pregnant? I thought I'm over it completely and back to normal, and then I hear my cousin's pregnant. I can't even explain to myself why I feel this way, it's just bitterness and jealousy and I don't want to be a bitter and jealous person. I hate myself for feeling this way. Why can't I make peace with these feelings! I was feeling so positive today and now I feel myself spiraling into that dark place.