Dear Herb,
looking at the photos it appears that there is very little wind. In such conditions flat sails and the wrong mast rotation and the attempt to steer into the wind at all costs kills boat speed. As Rob already mentioned the trailing edge of the mast should point to leeward. In your pics the trailing edge seems to point to neutral or even to windward - which has disastrous effects for the flow over the sail and kills much of the lift the sail and mast can generate. Try mast rotation first - that is assuming you can rotate the mast independently from the boom. Then again like Rob said more draft (deepness) of the sails could be in order. Free everything up a little bit if the wind is light. If you look at airplane wings - the faster the planes are designed to fly the thinner the wing sections get. Low speed - deep draft; high speed little draft/thin wing sections.
But do not free the clew of the mainsail. Instead tie it down as hard to the boom as possible to maintain enough tension on the mainsail leech. You do not have a vang to tighten the leech. So all you can do is tie then clew down to the boom as much as possible to keep enough tension on the mainsail leech.
If your proa is going slow do not try to steer too high into the wind. Try first to pick up some speed to get laminar flow over the rudder blade. If you steer too hard the flow over the rudder will get turbulent and the rudder stalls. The boat is still pointing high but slows down and starts drifting more sideways then moving forward. With more wind and higher speeds of the proa through the water this problem should disappear.
Just my limited advise from Laser and some Hobie sailing.
Perhaps Dough could offer some advice from his vast experience with the boat?
Good luck and you will learn quickly if you keep trying
Heinrich