Here is a list of the minimum amount of hit points (meaning life and es and that can be restored by leech or Life Gain on Hit):
Level 40: 1k
Level 50: 2k
Level 60: 3k
Level 70: 4K+
These numbers should only be below the minimum if you have one or more of the folowing:
Mind Over Matter
Arctic Armor
Block of 50% or higher
Phase Acrobatics (This includes all dodge nodes prior, including Acrobatics)
The numbers can also be less if you are a summoner. This is because you have a cloud of minions that absorb all of the hits for you. This also assumes that you have correctly built your summoner and don't spend any points until you get all of the minion nodes.
Now, you say you have ~1.5k life and are under level 60. This means you need to invest more points into life nodes, get gear with life attributes, or find a way to mitigate damage so that you don't need the life. Here are some of the things I'd recommend:
1. Grab the Diamond Flesh notable at the bottom of the tree. That's 12% to elemental resistances and it's two points away.
2. Grab Mind Over Matter. You have some points invested into mana regen, and should have enough to keep this running.
3. Ditch Conduit. Unless you play in parties more than you play solo and generate charges like mad, don't get it.
4. Grab the Clear Mind notable. Two points for some chaos resistance. Very worthwhile.
5. Grab the three 18% resistance nodes in the southern Scion starting branch. You grab melee physical damage, and there's a 15% node right after those. Grab that too.
Iron Reflexes:
If you need armor and don't want to change supports, get this.
However, if you have extra supports or specifically want to use evasion, then use Blind. Blind is a great way to increase your survivability, even if you get this. Just keep in mind that you'll be based on a 5% chance to evade instead of whatever chance you have now. Blind affects enemy accuracy, and is more effective the more evasion you have.
Endurance Charges:
Ditch Cyclone and use one of these ideas:
1. CWS and/or CWDT with Enduring Cry
2. Leap Slam + Faster Attacks + ECOMS + Stun
3. Leap Slam + Melee Physical Damage + ECOMS + Stun