Health degen comes in two flavors: conditions and hexes. Mesmers and necros typically apply hexes. Know your enemy and bring appropriate hex or condition removal if you're using heroes. If you're only using henchmen, you might be a little more limited, but it's still doable. Also, consider preventative skills. For example, necro casters are generally slower and more susceptible to interrupts. Bring interrupters is another way of stopping hexes being stacked on you. For PvE you shouldn't have to bring any heal skills on your own bar. Depend on your monk, even if they're AI controlled.
Warrior's Endurance is for energy management, not health management. WE is generally used for spamming attacks that use energy instead of adrenaline, such as Power Attack.