The next problem would be healing myself in combat if I really need to. Short of a cleric casting harm on me, I have few ways to heal large amounts in short term bursts.
You're a lich. Just teleport away, and touch yourself for a while. Hell, even death is just an inconvenience.
I'm sure there are probably some monsters you could summon that can heal you, also. (I just can't think of any ATM...)
And you can always put ranks in Use Magic Device, and get a Staff of Harm.
Craft Contingent Spell: Harm, is another option. The clerics can provide the Harm spell.