Philly,
If you asked this on other forums, since we're mostly about Smoking, you'd probably not get much of a reply.
BUT, here in the Friendly Forum, we'll help people, even those who use crock pots, ovens, etc. You'll just get a little friendly testing.
If you had a Smoker, it wouldn't be a problem, but you signed up on the forum, just to get an answer, so here's the help.
First, what you're cooking isn't a full brisket, only part of one. A full brisket actually weighs more than 7 pounds.
Second, don't cut the fat off. That's needed to make it moist and tender.
Third, you're cooking it too hot and too short. If a brisket is tough it's usually because it's been undercooked. 2 hours is certainly undercooking.
Our concept on this forum is LOW (as in low temperature) and SLOW (as in longer cooking times).
Try this.
Take a bottle of Italian dressing, the zesty kind. Double layer a pan with this, and then add your brisket, add the dressing. Wrap it up real tight. Set the oven for 225 and cook it for 1.5 hours per pound. Don't trim the fat off. It will actually keep it moist and after it's done you can just scrap it off.
When you take it out of the oven, if it's not so tender that it falls apart, just put it back in for another hour or two.
But, that's the oven method.
Smokin'