Angelina,
it does get better you are just barely out of surgery!! I suspect a lot will come back but you must give it some time; it is actually amazing how much you can and will adapt and compensate. (Although YOU may not think so).
Then there is this, there is a huge variety how clearly people speak anyway (accents and all that, just look at Arnold.. ok bad example). One way to combat your problem is to increase the visual portion of teaching (use more graphs figures/handouts).... or the ppt lecture from hell!
I still have problems with some words too.... just try to say magnetic susceptibility quickly.... same with assassin (although that word I do not use that much in class). Also consider this now and again: we are lucky to be able to have these problems.

M