so...where did you do your cutting that was uncomfortable?
i cut all of my fabrics in my sewing room on my cutting table. it is not necessarily uncomfortable- not sure what the problem was-
it is important to use a table that is the correct height for you though- and never try to use your rotory cutter while sitting down- you should be standing at your cutting table.
there are videos and tutorials about proper ergonomics in the sewing room- you may need to check them out-
just do a search for sewing room ergonomics.