Forgive me if I missed this but what kind of therapy are you in to cope with your brother's attempted suicide? If you're not you really should be.
I lost a family member in 2005 when she was 8 years old and I wish I had seen a therapist because though my friends and family understood that I was traumatized, my actions still drove people away. If someone didn't call me back within an hour I went into hysterics thinking they had died. I really needed a professional then and if you're not seeing one now for this, you should... that way you can learn to cope with your feelings as opposed to letting them affect how you relate to others in your world.