17 with attachment disorder??

I’m 17 and ever since I was little child I hated going to school. I wasn’t ever bullied or stupid or lazy but I hated going to school. Still to this day I just won’t idk why. I suffer with severe anxiety and hate being alone. Could it be that since I was so close with my mom my entire life I’m dependent on her? Maybe in my subconscious I know she’s my home and I know I could always count on her, and that’s why I won’t go to school or anywhere alone in fact? Because in my heart/or from my anxiety I know I’ll be let down and doomed to be alone when I’m away from my mom? I just always even when were arguing feel so secure when I’m with my mom, even if we’re not ever in the same room. Idk. Growing up it was always just me, her and my brothers. I’ve always had one close friend growing up every year but every one of them moved, and I always feel alone, so my mom is my safe place. Idk I’m not stupid, my teachers say I’m one of the brightest most intellectual students they have, and are shocked I’m one of the few that won’t be graduating (all due l absences) what do you guys think? Is this separation anxiety? Could I still have it at this age? I’m not on anxiety pills or therapy, I don’t believe in medicine and I’m not a open up my feelings kind of person. What do you guys think?