The XP system is designed so that not only do you need an increasing amount of experience for each level, but as your level increases, the amount you get from creatures you kill decreases.
Between the two, you have an exceedingly difficult time getting above a particular point. Without using a mod to enable creature respawns, I'm not sure it's possible to get enough XP to wear the dwarven pride armor. The only place in the game which respawns with creatures to farm XP is the Savanna, and they're of such low level that by now (level 37) they'd be almost worthless to kill.
A mod which enables respawning would be one help. Another trick is to put off doing your questing until after you've explored everywhere. Quest XP doesn't decrease as your level goes up while Kill XP does. So to get the highest amount, you want your Kill XP at lower levels and save your Quest XP until higher levels. With careful exploration and use of in-game magic (no console cheats are actually required to do this) it's possible to get anywhere in the game except for the swamp before solving any of the quests.
If you're playing on a game console and can't use mods, the trick to getting the highest level is this:
1) Get through the opening dungeon as quickly as possible. Finish the tutorial quests, but don't accept any normal quests after getting the stabilizing stone. Don't kill any other groms on the island.
2) After getting the stabilizing stone, immediately go to the savanna and start hunting the naturally respawing creatures (baboon, ostrich, warthog, cheetah). Leave the ants, rhinos, and varn alone.
3) When you've farmed yourself up to about level 15, you're not getting much for the respawning creatures any more. Start killing the non-respawning creatures like ants, rhinos and varn. Go back to Alsorna and finish off the groms.
4) Climbing over rocks, it's possible to get to the other side of the Bayan gate without opening it. Clear out the desert on the way to Hatmandor.
5) Put together an amulet of water walking using the "enchant" carrier card (it's possible to create an amulet of water walking using the area effect card, but it won't work for your purpose). Teleport back to bayan and run to the west edge of the island. Using the water walk spell, walk to New Ashos. You'll have to keep recasting it every 20-25 seconds or so, as you cannot cast while swimming. You *could* create a waterwalking potion, but using alchemy requires solving one quest and getting the necessary reagents requires solving a second one, and you're trying to avoid questing, remember?
6) Once you're in New Ashos, buy the boat at the southern docks. Now you can explore the rest of the world by sailing. From here, you can reach any spot on the map except the swamp, as that requires going inland on Elkronas, which is impossible without a mod. Except for that one spot, you can reach everywhere else (including The Swallows and the Castle Vahkmaar area) by careful exploration and a combination of running and jumping over rocks. Unfortunately, I can't tell you where the perfect locations are for fear that Reality Pump will nerf them in the next revision if I describe exactly where to find them. But I guarantee they do exist. If you get teleported with a "you lost your way" message, you found *A* path, but it wasn't the right one. There is at least one way into every area except the swamp (and it's possible that there's a way into the swamp that I just never found)
7) Once you've killed every living creature you can find, go back to Alsorna and start doing quests.
If all that sounds like too much trouble, you have a few other choices:
a) Play a different game.
b) Get the PC version so you can use mods. I'd recommend using WorldMerge.
c) Figure out how to defeat Castle Vahkmaar at level 37 with orc slayer armor.