What about the rotary cutter that fits into the slot on a special ruler forgot name . Also look at westlee tools they may be useful. My problem slightly different . Have to cut right handed but my left hand is weak and I have difficulty keeping ruler still. Westlee have a piece to hold fabric which means I can use a handle and hold in one place. No walking up the ruler. Unfortunately left hand too weak to cut fabric. Personall the name unable to remember may help you. The rotary is specially designed I have found I tend to push it with the palm. The blade fit snuggle in the slot on ruler and slide up. New blades on a more regular basis than normal also help.