I'm finding it very hard at the moment too. I write all the music for my band, it's actually really my baby, everything is written and designed by me, the only other people are the guys who help me bring it all to the live stage.
But our last gig was meant to be something of a milestone for us, we finally got a supporting slot at our local "good" venue, the Cavern in Exeter. I told the guys the moment we got offered it that we couldn't mess up, we had to play the best we've ever played as a lot of good bands go through the Cavern and shortly afterwards get signed or otherwise have something else good happen to them.
I tried to get a practice sorted, a couple of the guys were up for it but one in particular said it's ok, he'd practised a lot on his own and he promised me nothing would go wrong on the night.
We played an absolutely abysmal set. We had tech problems, but that's nothing to stop a good performance. The guy who made me the promise and said he didn't need a practise messed up MASSIVELY on 3 seperate songs out of a 5 song set. To say I felt betrayed was an understatement.
So now I'm considering just letting the band die. This thing was my biggest dream and someone I trusted killed it in one fell swoop. I don't even want to show my face at the Cavern again because of the sheer embarrassment caused by our fumbled set.
So I feel where you're coming from, except I've decided to take the easy way out and not fire anyone, just tell them I'm not doing it anymore. Seems easier. :?