Take a look at stoneskin and all the limitations on it.
1) It gives dmg reduction 10/adamantine so it only absorbs 10 pnts from any one attack and there's a way, albeit challenging, to get past that.
2) It does nothing for energy attacks.

It's 4th level and has a 250gp material component. It does last longer and can absorb more in the long run, but yours will absorb one really powerful attack that might kill someone. Stoneskin won't.

Plus your spell enhances healing.
Plus your spell blocks out undead.

I think it's dramatically overpowered for a 3rd level spell. I think you should probably raise the level a lot and also maybe make it more focused. Is it a force effect that blocks things (like mage armor or wall of force) and therefore maybe blocks straight damage, or is it a positive energy effect? Maybe the latter enhances healing or even give fast healing while also blocking undead or doing dmg to them if they attack.