I have a Lovark lv 60 a Groudon lv 50 a Sceptile lv 47 a Loudred lv 40 a Golbat lv 40 And a Hariyama lv 40 and I cant beat drakes salamence lv 55 any suggestions

You should get a Trapinch in in the desert by catching it and train it to evolve all the way to a Flygon and train it to level 60. Let the flygon learn dragon and ground attack moves because dragons weakness is dragon. and when your battling drake use only dragon attack moves only to kill it, since drake's salamance only knows how to use ONE DRAGON TYPE MOVE AND ITS dragon claw but drake uses mostly flamethrower and flamethrower doesn't do a lot of damage to a ground type. .
________________________________________________________________
OR JUST GET A WAILMER TO 40 EVOLVE IT AND LEARN ICE BEAM AND USE ON ALL OF THE DRAGON TYPE POKEMON
________________________________________________________________
.
P.S after you battle drake theres stevan and he's a lot stronger.