Ventingggg. 😢😢😢😢

Well my brother is almost 24 and is engaged to a 35 year old she has 3 kids with 2 different dads, then has one with my brother, and she just found out today she's pregnant. Do I have a right to be mad, sad, depressed... I've been trying for 3 years and 2 months like I can't even get pregnant. And been on fertility treatment and she's had 4 kids and now pregnant again and she only missed 1 day of her BC. I'm like what to do. I'm going to be doing Femara soon. And I'm still like what the fuck. I'm so upset. I paint a smile on my face when she's around and it's like I only wish. Like I'm married, and I'm stable, not living off of the government, and have to pay like 500 a month for fertility and they aren't really stable. I don't know anymore... I feel like giving up on everything. She literally just gave birth to my blood niece February 18th, 2015. And now... sorry I just had to vent a little because I'm so upset. Advice??