When family aren't there for you

I have found since mum died our family glue has come undone. My brother is not coping my dad is not coping. I’m trying to help them. But it’s hard. Me and dad are as close as ever. But my brother is pushing us away. He has always been a mummy’s boy. And as a result is a bit of a spoilt brat. I’m trying so hard to maintain the relationship but I don’t think he’s interested. He wasn’t that interested when mum was alive. It’s even harder now. I have to keep trying for mums sake. Bit how much do I take of not getting anything back.