Thotful, congrats on the pregnancy. That is awesome news. 13 weeks is a great sign. Do you know how many babies?
I think you might be reading into things with your brother. He was polite and responded to your email. I don't think that is a big gesture. There is no need to keep restating your boundaries. Your family knows what they are. You might just need to accept that as long as you are married they don't want a relationship. While that hurts most of us adult children have fractured family relationships. I also think you may be looking for too much validation from them. I am a recovering alcoholic myself. No one in my family much cared. I just got "I am glad you quit drinking". That's good enough for me.