No cutting yourself! I have nightmares about that! How bad was it? I often wonder how many quilters have had to have stitches from rotary cuts. Maybe none I hope!
I drive people crazy cutting toward myself, but no one taught me how to use a rotary cutter. Graphic designers (me) always cut down which is toward yourself. We have great control over our blades and know the consequences of dull blades and not paying attention.
Sharp blades are the key. If you can get them for 75 cents a piece, switch them out daily. Your arm will thank you. Cutting with a rotary blade should be like cutting through softened butter. If it isn't, you need a new blade or a new elbow. Your choice.