Your father’s support for your music is wonderful, but the insistence on how and how long your practice are extreme. Do you know why your father has such a stake in your music? Does he see it as a way for you to have a good life? Is he regretting not having a music career himself? Does he think that by keeping you inside and practicing he is keeping you safe? Something else?
If you understood his reasons, you might think of a better way to talk with him about your need for some changes. I suggest you find a quiet time to ask him about it. If you want a chance at getting an honest answer, approach him with curiosity, not anger.
Do reassure him that you do love your instruments and that you are committed to becoming an excellent player. Do your best to stay “adult” in the discussion. Don’t argue. Listen. Respond with reasonable suggestions for changing your schedule. Leave words like “freedom” out of it, since that activates him. Do respectfully remind him that you need your pc to do your school work which is also important.
That being said, it’s never acceptable for a parent to be violent with a child. It speaks to a high level of frustration on his part and his inability to figure out how to motivate you in any way. Not knowing how to manage his own feelings or how to talk to you, he lashes out. That doesn’t make it okay. It isn’t.
You didn’t mention your mother. I hope she is in the family and that she can provide you with some support. I hope she is able to be firm that his violence isn’t okay, no matter how frustrated he gets. I hope she can help you negotiate a reasonable schedule for practicing music, doing homework and some household chores, and seeing your friends.
If your mother isn’t able to help, I hope you have a relative or adult friend (your instrument teachers?) you can turn to who can help you talk with your dad about the appropriate amount of time to practice all at once. Often adults like your dad are more willing to listen to another adult than to their teen. (Yes. I know. That isn’t fair. But sometimes it is more important to do what is practical than to try to change everything at once.)
Please don’t let your music become a victim of your argument with your dad. You have a talent that deserves nurturing. I hope you can find a way to hang onto all that is good about being a musician in spite of the pressure from your dad.
I wish you well.