You got frost nova and Sheep on a castsequence?

/castsequence reset=30 frost nova,,,
/castsequence reset=30 ,frost nova,,
/castsequence reset=30 ,,frost nova,
/castsequence reset=30 ,,,frost nova

That should help take care of the melee, if you're in melee range frost nova + blink/move away.

The AoE spam button you use, i would almost suggest that you delete it so you get rid of using it. :P

It's just far from as effective as other spells, blast wave/fire breath + polymorph on any chars besides the one your dpsing should help a lot with lowering the damage. CC also buys you time, so you can think about what you're doing or want to do. Check around to see if there are other alliance in coming etc..
Stick to flash heals/Prayer of healing and spam Prayer of Mending when you can. That AoE spam doesn't do that much damage and it really doesn't heal enough. Just use normal casts, you'll get lossed and you'll learn how to deal with it. Mostly CCing them makes things like that a lot easier.

If you're able to upload it on filefront so it downloadable there or streamable that might be usefull. Since i can't see what spell you cast, can only guess by checking the castbars or see the AoE spam :P

What are the specs of your mages/priest? Speccing the mages frost with some sick Shatter combo's can be brutal. It's a lot less cooldown dependant then fire/arcane. Which is something you might or might not like. Mostly personal preference
I really suggest you spec the priest deep discipline. REALLY. Pain Supression will save lifes a lot.

edit: just checked your other post, nvm the priest's spec.