I need help improving my game

I've been playing for awhile now. I seem to be stuck in a rut. I'd like to think I have a firm grasp on the play mechanics but my record says otherwise. 347 wins in 870 games lifetime for a 39.89 winning percentage and i'm only level 8 with 86 trophy stars. When i play games that count towards level I can get one win away from leveling and then drop however many in a row and end up back at the beginning of that level. This happens constantly. In Arena play I think I have only won all 6 games once or twice. There have been a lot of times when i have started off with 5 straight wins and then two straight losses. Lately my arenas have just been two losses without any wins.

I've read guides on what cards are good value for the trade level and at the different phases of the game. Those help but not enough to overcome the trade row where my opponent seems to win the race for the power cards most of the time. Even at the beginning I get the short end most of the time. Let's say my opponent is going first and has 3 cards and the opening trade row has a Supply Bot and the rest are junk in the early game. If he has even one viper in that hand he can't buy it and i could on my first turn. With very few exceptions he has all scouts and gets it before me. i then get to choose from cards that I don't want any of, only to then watch on as another good card replaces what i just got and he gets that too. It usually snowballs from there. I love the game but I hate how often I lose!