Pretty much that's the only way real heals are coming i n heroic. Even with a rog lv or 2 tossed in and a gs item that 39 umd is a toughy. Not sure how much umd you need for a cure serious wand.
And even in epic levels cocoon depends entirely on not using up the buffer. Cast it, get smacked 2 or 3 times quick and it dies a quarter of the way before fishing its ticks. lol ive seen so many of those pure fighters rage quit in epic elites. Though I don't see a whole lot of mostly fighters anymore anyway.
But ya as said before stack the living **** out of heal amp. I mean forgoe all in the effort of getting hamp. Get it on gear, get it in enhancements, epic levels, just jack it. Then when you do get to epic levels and it counts as a cast (sadly you don't have rog or wiz or something to make scrolls and wands heal more) you find something with 150 devotion and like 20ish spell crit so that any time you do cast cocoon the first tick will be your lifeline before a baddy smacks ya.
And finding any sorce of max dodge cap will also help you. Stack the **** outa that one to. Your not dieing if your dodging. (Unfortunately the kensei reflex save dodge cap enhancement teir 2 does not give dodge cap its brokeded) But theirs feats to take ( You got enough) other enhancement tree's and some random named gear that adds to it. After that displacement. Even if you have to scroll that sucker every 30 seconds its gonna save your hp tremendously.
Well, have fun surviving.
Through avarice, evil smiles; through insanity, it sings.