When you send the herb runner out (for ingredients for the strongest healing potion you can make), send the other two for malachite ore and diamonds, which you can sell to get enough gold for upgrades.
Have you gone through your inventory / chest and sold anything you are not going to need?
Have you put any skill points into Regenerate?
If you are playing a melee character, invest some in Life Leech, otherwise try Potion Efficiency.
Learn Mana Efficiency (level 5 drops mana cost for spells, and summoning your creature, in half) and Healing (level 1 is probably good enough).
If you have any jewelry with enchantment slots that you expect to be able to hang onto for awhile, and some spare malachite gems, you could add a couple high level healing auras. If you don't need resistance boosting enchantments, you could add Life Line enchantments to some of your armour.
If you reload at malachite veins until you get at least 1 gem (2 are not hard to get, 3 can be had with a little patience or luck, and 4 are possible but rare), and get all you can from quests and merchants, there should be plenty. I missed a couple veins and still acquired 28 throughout the game.
Malachite gems are needed for all level 10 enchantments (so I stuck with level 9 most of the time, since they have almost as much of an effect but use common ingredients), or for any healing aura (so I only used level 10 healing auras, after being lucky enough to find that enchantment formula in the cellar of the Broken Valley enchanter).
