Hey girls, i didnt know where else to turn, so i came here. I just really hope you can help

As everyone else, hubby and i are battling infertility. Ivf cycle no 1: cancelled (Ohss) Cycle no 2: negative cycle no 3: tww (not confidenent with this fet). But anyway, we are on the ivf rollercoaster and have been trying for 4 years. The biggest problem is me, hubby has a low-ish sperm count, but im the one with the weird ovulation.
Anyway, my brothers girldfriend has recently had a child, it's a month old. They were never planning to have a child, it just happened. When they told us, it was in front of a heap of people and my reaction was nothing like i imagined. I broke down, balled my eyes out. But anyway, now im getting the grief from my parents to see this baby, but i really cant bare too. Its not that i begrudge them, or im jealous, its because she could do so easily what i want so badly. Even seeing photo's of this beautiful little baby make my eyes well up.
I really miss seeing my brother and his girlfriend, and want to be the best aunty, but its hurts so so much. (trying to type through tears) It just makes me realise that im failing in the area i most want to achieve in. I feel like no one understands apart from hubby, but even then im unsure.
Infertility is a bastard. Ivf is worse. Its not just the outcome of having a child that worries you. Its the scans. Are my eggs big enough, do i have enough, do i have too many, is my lining any good. Its the meds, its the epu, the transfer, the tww, the finacial side, its everything. So whilst we struggle to get through each cycle, and it mentally screws you, we have other stressors. Family life, stupid expectations, family that doesnt understand, work pressure.... Its never ending.
Ive had my cry, i feel a little better now. Please, am i crazy or being silly?

Thanks girls
xox
Roller