wearing thin

I'm going to try and keep this short. I have had lots of emotional problems in the past but I am stable now with a newborn I love more than anything ever. Someone very close to me, my brother, is going through an extremely rough break up right now and I'm trying so hard to be his rock and support system. Our childhoods weren't horrible but kinda weird. When my dad left my mom imploded, I was 10 and she began cutting, having huge breakdowns, hiding in her room all day and night. She kinda taught us that when bad stuff happens you just get suicidal and freak out and cry for help. Not to be strong and push through, so now my brother is kinda imploding. It's been a month and now he had began self harming and just very worth is me. Don't get me wrong I know he hurts, but at some point you have to choose to be depressed forever or allow yourself to just begin to heal. I am getting exhausted, what can I honestly do? I'm trying to teach him mindfulness, I talk to him every day I tell him I'm here I love him I feel I've said everything I can. Just needed to vent and hoping for an option, I don't want to end up being mean but a part of me wants him to suck it up and try harder to help himself., I'm so tired of my whole life all this shit it's wearing on me. I'm so mad at my mom for not being strong and showing us how to deal with our problems productively.