How to sustain pyromantic pact

Hello i come with question regarding the infernal flame how to make it viable because im having trouble sustaining it in demon form and regular form, i keep dying to it and it's frustrating me because I love the concept of it the demon caster fantasy if you will.

Right now im spec'd in demon form and infernal hound because of the sustain issue.

I know that you need lots of hp and hp regen to make the demon form sustainable and I'm doing a good job with that so far i also have capped out fire res(I'm on cruel)

Right now im following this passive tree that is found online https://poe2db.tw/us/passive-skill-tree/AAAABgEBeh5xXUj7e2KX-ZbvUzN2R6wSg0mdBtuj7cfwucPRwZvO3mfhbhFoIai24-fiwWgUwnFR7-uzPVoz9i2aW1uaAi4sZpk89ItNAz4NFzBXp2INrdLL54NfcdwaYAPIHNL9-LNLUtakj6JlYE8L4emTJ6xxFlYdd_A0wfbpGvK8sSDWimIXf5WzyDCaqtAuWZBq7UFVjxXWG-Fn0df2ilOLaGXpgWnKDXb0IqGT9DahxhHDaqAoehgJzbPpiSwLQ8Q8omA2BLDzadp78lLQffrA9QxJNh4p09jwXhI5PyhjHrNca21LgkOOhiSzkW9e3k46TsWxLowAAA== im not max level yet so I'm missing a portion of the tree right now im lvl 53

Any tips towards what gear stats to use maybe change some things to the passive tree.

Edit: i also don't have altered flesh yet because I haven't been able to clear a trial yet for the next to points but I have capped out my fire res in preparation.

Bump

I'm using Demon form + Pyro pact too.
My approach to sustain DF is by using damage recouped as life and Pyro pact's self damage.
Therefore, I avoid any life nodes or max hp on gears, and taking Heavy Buffer node to reduce max hp.
Then as long as my max ES is 4 times as my max hp, I'll take like 30% of my ES for infernal flame reset.

Another concept to sustain Demon Form is by using MoM and flat life regen on gears. And that also need you to make sure max hp is low enough.

In conclusion, if you're taking Demon Form, you'd better lower your max hp instead.