Feel like I have too much downtime as a Necro? Lvl 16-17

[BarkingSpider]

Hey guys not sure if I am doing something wrong or not, I've been soloing in Oasis since 16, I actually just hit 18 a few mins ago. My normal rotation on blue mobs is Engulfing Darkness > Fear > Heat Blood > Fear > Send pet (mob @ 60% hp) > Fear 1-2x depending on HP. If it's even con mob, Ill do the same thing except I'll add a Heart Flutter after Heat Blood. I usually always send pet in around 60-65% hp because if not my dots won't last to duration and I always feel like I get less EXP if I don't.

The soloing itself is fine, easy, no problems. However each time I kill one mob, I use like pretty much 50% of my mana. So I'll kill 2 mobs and then have to wait a few mins to regen back up. I am keeping Death Pact up 24/7 by the way.

Just wondering if I am doing something wrong, or if there is a more efficient way to be leveling?

Also on a side note, I am so tired of seeing crocs and caiman, are there any other places I can go to solo at 18? I've been in Kurns and Unrest and they're often pretty packed and don't have room in groups without having to waiting an hour or more, so I usually just try to go solo somewhere so I don't feel I am wasting time.

Thanks!