I live in AZ and my sewing area faces S/SW and I have sun until after 5PM daily. If I don't get in to sew until the afternoon it's ten degrees hotter than the rest of the house. Besides the ceiling fan, I use CLF light bulbs and use 3" thick sheets of foam insulation. I cut it to fit the entire window opening and it works great to cut the heat gain from the sun.
I would try the portable AC unit, vent it through the window, cover the window with the foam insulation (making a cut out for the AC vent). I swap the sun light for reduced west afternoon sun anyday.. Good Luck