You have every right to be sad about this, it must be very hard for you and your brother.
I had similar feelings when my brother moved away several months ago. The feeling of loneliness will fade over time, if you can try to talk to your brother on the phone and talk about light, happy subjects as much as possible. Let him talk about the control-freak and let him know you care about him and miss him, but then change the subject and talk about something positive.
Your brother would feel very good if you keep an optimistic attitude and support him, but help him to feel better too. If you do this, both you and him will feel better about this bad situation. Trust me, he will get out of this situation soon. Just think positive and help your brother.
At anything, keep yourself moving just to help your brother and your family because this must be hard for all of you.
Keep your strength thorough this! This will work out. *Hug from me*
Alli