I've been wracking my brain trying to figure out how to get this to work. My basic concept is a Goliath druid who goes running at baddies while raging (via rage subdomain) and healing trough regen. The druid is a half orc and I'd eventually go into deathless initiate and deathless master. Aside from that, I don't have a ton of ideas how to make this character more...durable. I'm looking for ludicrous survivability. Feats, items, traits, anything
It's not compatible with goliath, but the reincarnated druid is the closest thing to immortal that you can get on a PF player character.
That's not much to do with your concept though. For the druid that keeps on going and going you might consider a dwarf rather than a half-orc; they can get a lot of defensive benefits, and the Broken, not Beaten trait largely substitutes for ferocity. Deathless initiate/master aren't particularly helpful IMO compared to the dwarven racial feats. You might also look at the contingent spell metamagic feat to store up some healing.
A vampiric (or greater vampiric) weapon will obviously help keep you up. An aegis of recovery may be useful at lower levels at least. Some temporary hit points might help - the skin of Klendar the troll king can provide some.