You'll find this happens a lot. It's just a weird part of playing electric guitar. Tones that sound great by themselves tend to sound "full" and have a lot of treble and bass when you're playing alone. But in a band context, the other instruments take over the treble and bass ranges and you're left with a fizzy mess of tone you can't hear.
If you dial in a great sounding tone in a band context then play it isolated at home, chances are it will sound too mid-heavy, maybe even notchy and spikey in some of the high mid frequencies, and it probably won't have enough gain to really feel great in your hands.
This is normal.
The quickest fix, like Paperjace said, is to boost the mids (the fat switch helps too) and maybe lower the gain just a tad if the mid boost doesn't fix it. The best possible option is to dial in the tone at band practice, but not everybody always has the time, patience, or resources to do that, hah.
