There is nothing wrong with you. It is absolutely normal for you to be upset by your father’s behavior. Unwanted touching, staring, trying to see you when you are undressed, and isolating you from friends are not normal fatherly behaviors. From your description, you have every right to be concerned. He is overly controlling and invading your reasonable boundaries for privacy. No child or teen should be this anxious about her safety in her own home.
I worry that years of this treatment has worn you and other family members down. Your father has everyone convinced there is nothing they can do to stop him. Guys like your dad rely on secrecy and fear. That’s what gives them power. The reality, though, is that your father cannot keep doing these things if you and other members of the family make it clear that it is not appropriate and that it will not be tolerated.
If you feel safe doing so, tell him clearly, very loudly, and repeatedly that you don’t like it. But it is not just up to you. Tell your mother and grandparents every single time he crosses your boundaries. The adults should be putting a stop to your father’s behavior. If your family won’t support you, please talk to your doctor, a school counselor, or another adult you trust and ask for help. If you can, make an appointment with a mental health counselor. Counselors often know what steps to take to make you safe.
Meanwhile, start quietly working on plans for leaving home as soon as you can. Do well in school so you can go on to university or so you can get a job at graduation that will let you move out. You’ll feel a bit better if you start taking some steps to get to safety.
I wish you well.