My Guest Bedroom Mess

Ok so I am painting my guest bedroom. The colors are a A light tan, Turquoise Tint, and a deep walnut brown. So this was my idea. I painted one wall the accent color turquoise green. Then I painted the other 3 walls the light tan. Then about 10 inches from the ceiling I am going to paint a deep brown stripe. Well, I got all the walls painted and was starting to mark off the lines for the stripe. Well, I marked it all the way around the room and the 2 ends didn't match up. So now I am trying to decide if I even want the dumb stripe. I told my dad how I screwed up and he said that I pulled a Kim move. (Love ya Kim) Ya it was a pretty blonde way of doing it. Let me explain. I measured 10 inches down from the ceiling. Then I got out my level that is about 6 inches long, and drew lines with my level. Well, I didn't take into consideration that the walls aren't all the same height and I was about 2 inches off when I got back around to the start. So now if I am going to do the dumb stripe I have to do it a different way. But no matter what now I have to paint over my lines I drew on. I HATE PROJECTS THAT I SCREW UP!!!!!! Oh well, I'll let you know how it turns out.