Food for thought. ThanksBut there's even another angle. Perhaps, the one acting badly in the relationship might have been you all along and not your brother and he got fed up. Also, if you're as argumentative and defensive as you are here in real life, I can understand why he might have had enough. Sometimes, the way you think you present yourself to people and the way you truly are is completely different. And perhaps, your brother's partner though she may have flaws isn't so bad and she might have been right to pull him away?
Also, 2.5 years is very long. I don't know but in my opinion, if you truly want to see someone, you will see that person. Heck, you could have even visited your brother quickly at his home. Maybe your brother didn't want to see you, but unconsciously you might have been fine with it. I don't know based on what you said, it seems like you might have been judgemental on his life choice (not having kids), his stability, and the fact that he and his girlfriend are well-off. Your entire relationship with your brother seems off. Honestly, I have attended baby showers of people I barely knew and I've seen other people do that. And usually it is common for people to visit acquaintance when there's a new baby in the family. So, it seems very strange that your brother would send you just a congratulation text without trying to visit.
The other thing you might consider, is that perhaps, you guys never had the relationship you think you had. Also, perhaps, your family is just not as close as you thought and your parents didn't raise their sons to be close to each other in the way that you thought.