Guys I need help

I had parental controls monitoring my device, and I am now 18, I didn't get a notification to actually leave supervision, so I deleted my Google account thinking it would work and remove supervision completely. I then recovered it and tried creating a new one, and I then found out my device was still being supervised. Mind you my Mother deleted the family group, stopped supervision and showed me an eMail that confirmed that my device was no longer being supervised. So I've tried adding my account back onto my device, and I can't seem to, despite it being the one account that was ever on the device. I'm not being supervised anymore, yet my device is still being supervised. I can't do any of the prompts on the screen here because it requires a parent, who has already stopped supervision over my device and I've done so much with this account that I'm not willing to let it go. Please helps me if possible.