You do have a short stem, but it has a pretty good rise to it. How about a negative or 0 degree rise at the same length? I'm saying this cause the handlebar seems higher than the seat. I would not recommend this usually, cause most people are dealing with a bar that is lower than their seat, but you are dealing with one that is higher. It could help, but perhaps not; I would try to borrow a stem like that from the bike shop to see if it would work. Our bike shop always has old stems around that you can borrow to try out fit. I would definitely drop the nose of the saddle to see if it makes it better. You can always move it back up.

The seat post suggestion of a straight seat post is a good idea too, but I would try one thing at a time.

spoke