Here is a couple idea's...
Call a wrecker. The $50 or so would be small for getting your tractor out
Or, get a come-along. For $25-35, you would have something you could use again.
Get a Hi-Lift jack. For the $50, you could use it to winch, after you use it to jack/lift the tires a bit and block them up.
The drawbar is partially exposed. Get some planks under there, and a jack(you may need to dig it out a little to make room for the jack). Jack it up, and put blocks or planks under the tires. Repeat until it is high enough to easily get you out. Add those extra blocks; it would be bad to get it up just a little, go 2", and be just as stuck again.
I've put full size 3/4 ton 4x4's to the frame in the mud. Dig, dig some more, and jack/block it up.