The best for him without doubt, is to be with you. You found each other and under what ever circumstances, you should do all you are capable, to stay together. See it as a challenge and part of your growing process. You are confronting reality and in this you learn. He is with you and will support you as a faithful friend you can trust more than any human...
I am talking out of experience. Many years ago I met a German shepherd an older lady couldn't keep after her husband died. So I took him. I tell you: There have been a lot of difficulties, but I kept him and indeed, he became my best friend and we had a very good time together. I wouldn't have want to miss him anymore and we were together for more than twelve years, until he died in my arms, - but he is still with me...
So stay with your dog! Make your parents understand the importance this has for you and that you will love them even more, if they can understand and accept this.
Edit: What I wanted to express was, that your dog has an important meaning not only for you but also for your life. That means for example, that you need to work on your relationship with your parents and that you learn how to relate and response to your father. Understanding that you need to see him not only as your father, but also a person independent from yourself and so accepting his specific character. Now doing your best to make him understand your position. So that you come nearer to him. Your dog has helped you to go for this! Do you understand what I want to say? That's what is 'life' about and your dog is an important part of it!