/diy/ - Do It Yourself

Hey anons,
I have some property in the southeast that for some retarded reason the previous owner decided to randomly plant water oaks all over with no regard. Now that I want to utilize the land I've been having to remove them myself. They are about 12"-24" wide trunks, I don't know much about tree removal as I have never done it before I bought the land, but have spent the last year chopping them down and cutting them up with an axe. I'm able to fell, strip, and cut up about 1 a day with an axe, for a total of about 2 a week when working on it (about 30 total over the last year). My shoulders are killing me so I bought a 3' one man crosscut saw, I sharpened it with a bastard mill file, it's very sharp and properly done.
However the saw blade keeps binding on the oak after cutting about 1/2" in. The wood is very wet and the saw dust isn't taking out well, it's all stuck to the blades.
I'm thinking I could probably do it fairly easily with another guy manning the other side of the saw but can't really prevent the saw blade from binding and flexing when I push the blade, pulling is fine.
I haven't lubed the blade, but am not sure that would make a huge difference, maybe I'm wrong.
I'm looking for any suggestions,
are oak trees really this hard to cut?