As a relatively new player, I'm also struggling to win. We have a small 1250 point local tournament going on (one game per week), and I'm currently sitting at 0-3 being either basically destroyed or just not having enough bodies to score objectives because the other army keeps summoning stuff. I still like the SCE and I know I need to get better with it, but right now it's getting close to being autolose for me.
I mean, one of the games was in Ulgu against Khorne and then we roll the characteristic that made the maximum range of attacks or spells 18". I go first and then the other guy gets a double turn... I almost ragequitted right there. Just seating there watching how my army gets erased by Bloodthirsters is not fun.