it's probably helpful to include what div you play in (if at all) and what skill level you want your mentor to be, because all I can tell from your post is that people have gotten mad at you for missing people's buffs on rollout but that can happen at nearly every skill level (that being said it's easier now that scouts can chariot you to mid)
Another thing to think about is if you have any demos to review (match, scrim, pug or whatever) or if you just want someone to show you the heal order or something simple like that (you could probably download stv demos of invite matches and watch medics povs if that's what you need to learn)
It can be super frustrating playing medic at low levels and with unorganized teams like in pug champs, I'd you haven't already you should definitely try to find a team and practice in a more consistent setting (again, can't tell from the info on the op if you've ever even played in a league so sorry if this comes out as obvious or condescending)
Edit: it appears that you posted this thread twice a mod should probably delete the other one