It can certainly be done but takes much dedication. There are some things for which it's best to have a teacher, but those things come after all the first year stuff (first year is basic grammar, reading, etc.). For example, in my second and third years we focused more indepth on syntax (which you can do on your own) but we also did things such as diagramming, textual criticism, and exegesis, which really do need a teacher. Our focus was on biblical studies so some of these things may not be necessary to you anyway. :) But if you do find yourself eventually at that point, I can recommend some great books.
And of course textkit is always here to help!