If I am reading this right you are only using a regular ruler? If you are that might be making it a lot harder. I almost away use a large cutting mat that has the slots in between it.You just line up the fabric then put the rotary cutter in the slot and cut. When you are using a small mat or a ruler it's harder to get a good grip with your other hand to hold the fabric in place. (Make sure your hand isn't too close to the blade of course). I am left handed also and I do think it makes it a little harder. I am especially hard on the blades because I basically have little coordintation.