I agree with the just enjoy your session wheat that you made, but......
You could always make a jacked up recipe and do some blending. BeerSmith has some formulas in it to show what adding what to what makes what.
Yooper's add some DME, I'm sure would work too, but I'm not sure what it does to taste, especially with something so light. Yoop, do you find adding it during the fermentation makes any taste differences? I really only use DME for my starters, so I really know nothing about using it otherwise.
Also, this is a good reason to measure your pre-boil and post-boil gravities. It allows you to become more comfortable with your setup and gives you some room for predictability for when you brew. Saying your gravity should have been 1.050 and turned out to be 1.034 means you should have (roughly, off the top of my head) had something like a 1.036-1.040 pre-boil gravity and wound up with a 1.020-1.024 pre-boil gravity. If your efficiency came up shorter than expected, you could have boiled longer.
I'm not sure at what efficiency you write your recipes at. I write mine at 80%, but I think 70-75% is normally what people usually do.
So assuming you wrote your recipe for 70-75%, you got roughly 47-51% efficiency. (Sorry, if my math is off, I'm doing this without my BeerSmith crutch). It really sounds like your efficiency is low, either way. I think it would benefit you to take some readings to see what you're getting out of your mashtun.
