I feel like a terrible person

I don't want to be bitter and sad and angry. I feel like such a horrible human for feeling this way on mothers day. I feel selfish. I've seen 3 woman today announce their pregnancy and i can't help but to feel jealous and bitter. Am i really a bitter person?? I've never felt this way about anything except when it comes to having a baby. I've never been jealous or envious of others. And today out of all days i feel like this. I want to be a mother. But i am not yet. And my friends keep telling me "it'll happen when it's meant to be" and "don't be sad it's just not your time yet" and that shit makes me so upset / mad. How can something hurt so bad to the core if it's not meant to be? Please tell me I'm not alone, i feel so broken inside