Pulling my hair out

Last week I ripped out my first sleeve on my sweater and started over because it just wasn't working, so guess what I just did.. yeah, I just took out 10 inches that I did over the weekend, I must be sleeve challenged. I can knit sweaters, arans, afgans ect. but I just am pulling my hair out over this sleeve! I am going to work some more today and hopefully I will get the decreases right this time. I wish I knew the formula for decreasing sleeves in the round.