If you want to ride straight up and down, get another handlebar, with a lot more rise. That would go well with your raised, and moved rearward, seat. Before spending the money on the bars, try raising the seat, and adding Ergon Grips, to see if that helps. You won't be out anything, as you can swap the Ergons to new bars later, and you might find riding with a slight lean forward (with proper hand support) a nice way to ride.
You should be able to straighten your leg, with only your heel on the pedal, without rocking on the seat. Then, pedalling with the balls of your feet, will result in a slight bend of the knee, in the bottom of the pedal stroke.
That stuff, with Ergon Grips previously mentioned, will make a world of difference in riding comfortably.