I have had to go no contact with numerous family members of my own. I did hear you say on live this happens a lot and we make up. Look into things like trauma bond, cycle of abuse , narcissism , bipolar rage, gaslighting, flying monkeys (posse surrounding and standing by narcissist no matter how wrong person is), deflecting & manipulation. Once you educate yourself on your situation with said person I’m hoping it will click that this is not going to stop, you will endure a lifetime of heartache. This is not how a parent should or would want their child to be treated or anyone for that matter. Who cares if your gunna be 18 you are his child always, he knows you stay he knows you put up with the shit, he knows if he plays the I am not well card ( which honestly he isn’t but that’s not a reason to manipulate people). You are showing him what you will allow to continue. You need to grab yourself up realize you can make this shit stop, leave , you and your gf have a promising future waiting, drama free fun. This is horrible to keep going through.