Need Help with Physical Damage Mitigation

I'm playing a MoM Stormweaver, so obviously I'm stacking mana as my source of scaling damage and defenses.

The problem is that I'm not really able to acquire any decent amount of armor without sacrificing all ES on my gear (which is converted to mana for a higher EHP base, since mana = life with MoM).

I'd also have to get a LOT of strength to wear gear with high enough armor to be useful. That's another problem especially in early progression.

In PoE1, we had phys damage taken as elemental damage to mitigate phys damage. Is there anything like tha in PoE2? I don't see how I'll be able to handle high phys damage other than scaling mana EVEN HIGHER rofl (maybe 4k mana somehow?).

There is a unique item like "Cloak of Flame Silk Robe"
X% of Physical Damage taken as Fire Damage

-Not sure if there is anything else like that.

Are you using the "Adverse Growth" passive?

"

20% reduced Life Regeneration rate
20% of Damage taken Recouped as Mana

it's pretty close to MoM on the skill tree and might help some.

Follow-up question are you using "Mana Remnants" - Buff skill to overcharge your mana pool? you may be able to support it with "Clarity" for 30% mana regeneration.
That's basically like having witch's blood ascendancy "sanguine".