Two words: Healing Signet
I went like my first 15 levels without it and was dying a lot. I heard about how good healing signet is and picked it up and the difference is night and day. If you’re still having trouble staying alive with Healing Signet equipped, then you’re doing something wrong. Don’t ever bother using the active on Healing Signet though. It’s not worth it. The passive regen it provides is what will keep you alive.
It doesn’t really lose its effectiveness until some time shortly after level 50. Around that time, you’ll probably want to switch to one of the other healing spells and should be strong enough by then that you don’t need the passive regen anymore anyway.