Stuck in GM2/3

I’ve been between GM2/3 a lot since end of S1. Trying to hit Celestial or Eternity only playing Jeff. I solo queue and trying to rank up. Not sure what to improve on to hit celestial. Got stats for all seasons, season 0, 1.0, and 1.5. Any tips or information is appreciated. Play style is mostly healing constantly and DPS when needed unless we have 3 healers and I could flank DPS