What should i do? I see no realistic way out.?

I just dnt knw what to do. And i need impersonal opinions. When i was younger my brother ualy ultd me. Iv always knw bt only recently has the repurcusions fuly hit me. Its feels like it just hapend. I went to therapy and i got ova what hapend. Bt recently my brother has come back to live at hme. I hate it. I cnt go a day wit out crying, i tink bout sucide al the time bt i wnt do it becoz its cowardly. Nearly a month ago i gave my mom a month to get rid of him, or i would leave. She tels me that making her chose is unfair bt i dnt knw what else to do. I have no close fam i cn go live wit. What is the right ting to do?