Nice game, and I hate it get troll'ed by an Umbreon everytime -___-.
I could help you with your troubles. Your team is currently good, except that you need more prediction skills (made easier with Team Preview), a bit of coordination for your Pokemon, and more speed. Some of your Pokemon could really outspeed a Cobalion easily. You could've killed my Dusclops with another Flare Blitz though and not-toxic'ing your Darmanitan would be a pain in my part. You could've also U-Turn'ed out instead of switching out to Slowbro, Bug > Psychic, therefore, damage to Slowbro.
A bit more prediction skills (through a lot of battles and experience), and just coordination. :)