The problem was not f5. It was g3. I just woke up, so my brain may not be quite working, but I believe that h5 was the correct move (or at least a better one). I'll look up some good From games later or tomorrow and post them.
From-Gambit

The aggressive Ng5?! This line is "refuted", but I have been itching to play it myself, since so few people know the "refutation" - I use quotations because I believe White can still pressure Black. Thanks for the game.
As far as the way to trap the knight, after Ng5, play ...f5 and then ...h6. Taylor's Bird's Opening book gives the refutation, but it is some homework, if you know what I mean... :-)
the From-Gambit goes 1.f4 e5.
Here is a game i jost lost: