To cut a long story short, I failed my trial on Mingle (which I was expecting), and I think a break from raiding might be in order.
Basically, as a priest healer I wasn’t experienced enough for Heroic ToC25 (not as disc, and definitely not as holy). And I was failing so much at raid-awareness (including little things like concentrating so much on healing my assigned targets that I let myself die – need to remember about Binding Heal!) that I was a liability to the raid.
So I politely said my goodbyes before /gquitting, and got an invite back to the old guild where I think I’ll stay awhile while considering what I want to do next. (Healing is actually pretty fun, and I might be up to the hardmodes after a lot more practice and experience – it’s just hard to get that near the end of the patch cycle)
It’s tempting to throw it all away and start anew on a new server, and try building up a network of alts like the setup I have on Dath in preparation for Cataclysm.
For now, though, I think I just need to let my wounded ego mend.