HELP!!!

If anyone wants to come help me paint feel free to! I am having issues! I am doing all the touch ups and I will touch up the pink wall, and get pink on the green, then I will touch up the green wall and get green back on the pink, then I will touch up the pink wall and you know what happens next. I think I finally have the colors fixed, but I am afraid to do the white on the ceilings!! I don't want to have to touch up the colors on all the walls again! I have tried using all the handy gadgets that are out, I have tried using a straight edge (somehow I got paint on the other side and smeared paint on the side I was trying to protect!), I have tried taping it off (but I don't tape well so my lines look like a drunk guy did them)... so now I am trying something different.. looking for someone who is better than I am, or someone that actually has a steady hand!! I feel like I am wasting borrowed time on this. I still have some trim stuff to paint, I have all the downstairs trim to stain and varnish, I still have to paint a second coat on the downstairs walls, and touch up the ceiling down there too! Deric is basically done with the trim upstairs and can start on the downstairs anytime, but I'm not done with the trim or walls yet! Arugghhh! HELP!!