There's nothing wrong with saying, "You're speaking too fast for me. Could you slow down, please?"
That said, if you really wanted a "special" word to fit your exact sentence, you could use the word "auctioneer" as a modifier:
*I find it difficult to keep track of and follow your auctioneer speech*.
Auctioneers are famous for speaking unusually fast (one NPR story began, "It's the familiar, but sometimes unintelligible voice standing out among all the rest: that fast-talking, number-crunching auctioneer"), and sometimes this analogy is used to describe people who talk rapidly outside of the auction hall as well. For example, a 2006 Boston Globe article about a political candidate began:
Sometimes he talks like an auctioneer, trying to cram just a few more arguments and anecdotes and ideas into each utterance.
A blogger talked about her hurried, impatient nature by confessing:
I am the sort of person that impatiently watches the toaster, walks like I am running and talks like an auctioneer. Doing anything slowly is against everything in my nature...
A reporter describes the astronomer he interviewed by saying:
He talks rapidly, of course. You know that. The Sky at Night only runs for 25 minutes. He has to maximise word content. So he talks like an auctioneer at 300-words-a-minute, snapping the end off words the better to cram them all in.
You could use this word in your sentence if you didn't mind being a little humorous in your request.