If anything this problem is even more acute in D:OS2. I am literally stuck on 2 separate playthroughs because I am unable to get enough XP to level high enough to enter the fort. The lack of XP is pretty much game breaking.
You can enter the fort at level 1.
And you can pretty much leave the fort without even fighting anyone...
I suggest you learn how to position yourself before a fight, lure enemies to more advantageous grounds, prepare traps for the enemies(barrels) before starting a fight.
Focus fire 1 at a time.
You can dmg and bunch up enemies if you teleport 1 of them on another.
Use grenades if your dmg is too low, you can make them with broken bottles or nails.
You can run from battles after killing a few.
Look at the enemies armor to see if the enemies are easier to be stunned/frozen or knocked down so that they cant attack.
You can get a free hit if you initiate the fight before ending the dialogue.
Healing potions are really easy to make if you dont have healing spells, there are some other good potions to look for, mostly just combine any plant with a empty potion bottle to see the result.
You have plenty of advantages to use against the enemies, plz dont just rush in there blindly.