Sorry to hear that...but yeah, never give up...brisket is the king of Bbq beef in my mind...love 'em now that I can get consistantly great texture.
Maybe on the next one try to foil after 160*, or as I prefer, a steam pan and foil tent to avoid pin hole leakage. Add some fruit juice or other liquid for brazing, and take it all the way to 200*. Then, rest for an hour or so.
I've got 3 in a row that I (we) really liked...OK, the third hasn't been eaten yet, but turned out good so far. If you want to pull it you can with longer resting, we liked the sliced better though...melt in your mouth.
Here's the second last one I did with methods and the works:http://www.smokingmeatforums.com/for...ad.php?t=79244
And the one before that in case you want to see any variances I may have done:http://www.smokingmeatforums.com/for...ad.php?t=78562
Give those a look and see what you think. It's not a traditional/typical brisket method...it leans more towards a pulled pork method. Basically the qviews I do are a diary of my smoke, start to plate.
Good luck on the next brisky, and keep trying. You'll find what you like soon, I'm sure. Getting the temps/methods/chamber temps right can take a few hits before you get it the way you like it.