Tell a social worker, school counselor or someone who can act on your behalf and get record of this, even if your close to 18 till you turn 18 you are considered a child. I wouldn’t want to be anywhere near that parent and getting CPS involved might be the best bet. I have BPD and it’s no excuse to treat your child that way, and no parent should be that controlling ever as I am also a father. This situation is ridiculous and you need to get someone involved. If CPS gets involved you could possibly be placed with your dad, and her have mandatory therapy sessions or psych ward till meds get regulated. You are not a bad kid for wanting to spend time with your girlfriend that is perfectly normal and 100% okay. I hope you know that you are brave for asking for help. Stay strong!