I didn't use two handed swords, but I think that damage range sounds about right for that part of the game.
Have you learned Bleed (up to level 10, when you have the level requirements and skill points), in addition to boosting two handed weapon expertise?
Other than random drops or loot from chests, once you get the battle tower there are a couple merchants you can check each time you level for better equipment (save before running your crosshairs over them, and you can reload until you get something you can use).
There are two black ring soldiers in the bunker where you need to get to to turn off the anti-dragon barriers; they will surrender, and one of them has weapons, armour and sometimes jewelry for sale. After that you can continue up the path past the depleted ore mine; if you keep to the left path when it splits, you go up to High Hall, there there is another merchant after you do a quest there. Taking the right path leads down to the Champion Harbor; there is a smith inside the building, and if you bring at least one of each of the 3 different zeppelin parts (found in wyvern nests) to the zeppelin master, you can travel to Aleroth, where there are 2 merchants who sell legendary quality items (as does the one in High Hall, at high character levels).
In addition to boosting the relevant stats to raise your melee, ranged and magic resistances, you could add enchantments to improve your resistances and/or your total hit points.
There may be easier opponents in another area you could do first, as well.
One skill point in Evade is helpful for melee attacks (the effect per point is not as good if you want to raise it to higher levels).
Have you invested in Life Leech? (at least 1 point)
Have you put any skill points into Regenerate? Not getting hit is best, not getting hurt is good, but failing either of those, healing faster is helpful.
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 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).
