[Kyburg]

Hey
I assume you guys are at the same school, so maybe try to see him then and find out if he still has his phone. Is there a nurse or similar person at your school you could speak to? If someone from the school were to get involved, it would greatly improve your position. They could either take him to a doctor themselves or compel his mother to do it.

Regarding restricting his activities, remember that you are still minors. Legally, his mother is responsible for him, which includes reasonable restrictions on his behavior. (Not judging whether this particular restriction is reasonable or not) It doesn't seem fair, but unfortunately that is part of growing up and becoming independent. You should maybe try to speak to her about it together and explain how much this relationship means to the two of you. Hear her side and see where you find commonality as a starting point. From there, try to reach a compromise between her rules and your wishes. Don't be confrontational about it, rather more diplomatic. Don't let her work you up. Keep your cool and negotiate.

Best of luck!