I am afraid to tell my family I am Muslim because they will disown me. Can I hide it?

Yes, it is allowed, and in some cases even encouraged, to hide your Islam, if it will cause harm to you, especially in the beginning where you are getting accustomed to being a Muslim.

There are enough challenges as it is with adopting Islam, so make it easier for yourself by not telling them right now.

You can tell them later when you are more independent and stronger in your faith.

Almighty Allah knows best.