~Don't forget that you have nado. Sure, drill rush has its purposes, but MT is much more effective in most situations due to its flexibility (to an extent, you choose its duration, and it doesn't have nearly as much as of a set path). Learn how you should use it, when you should use it, all of that jazz. This is the spammable move of MK (though spamming it is a bad idea).
~You seemed really nair-happy. A better approaching move would be a fair, a dtilt, or an ftilt. These moves have much better frontal range than the nair ever will. The fair and tilts also promote much better spacing than the nair does.
~Um...you didnt use a spot-dodge, a powershield, or even a roll in that match. You need to start using these basic dodging techniques to be effective at, well, any character in Brawl.
~Watch videos of other pro MK players to get more of a feel for how MK should be played. I even posted a MK vs Ike match link here, where MK defeats Ike. Hopefully this will help.
M2K (MK) vs. Azen (Ike) 5-25-08
It's a bit dated, but it should still do the job. There are plenty more videos around YouTube and the SmashBoards that you can watch. In fact, you should watch more vids =p you won't always be fighting Ike.
*Overall, it seemed like you aren't that experienced at playing MK =\ As mentioned above by several people, after you get the basics down, the main thing that separates a scrubby MK from a good one is proper spacing.