Without a support system, it is nearly impossible. We are made to dwell together and when you are ostracized like that and isolated and given up on, it can spell too much trouble. Advocate has offered help, that is wonderful. There's essential resources available. Hope it helps.
I'm sorry about your brother. It is unfornate he has lost a big part of his support system. This is probably a really hard time for him and I hope he can find some help. If he can get treatment he should be okay. Maybe he can find people who will understand and be a support instead of throwing him away. It is not his fault he tried to commit suicide, it is part of the disorder and the biggest sign that he not only needs help but loving people to help him through this.
Yes when people with bipolar disorder, schizophrenia or schizoaffective (or any psychiatric disability for that matter) go off medication symptoms return including suicidal ideations. People can adjust to life with treatment. As treatment improves so will recovery rates. Every person who is able to has the right to live in the community. In the United States there is supportive and supported housing for people who are able to live in the community but need supports and services. I believe that exists in other countries as well. You should be able to find out at the independent living center in your country:
http://www.ilru.org/html/publications/directory/international.htm#ireland