What level are you now?
If you run outside, there is a teleporter shrine just to the right (at the edge of the lake), that you may be able to use for quick getaway.
Are you just using the one save slot? With a new save before key events (entering new buildings, etc) you can easily reload and do something else first if you run into problems.
If you have any spare skill points, you could save and then try Firewall, or something (if you meet the level requirement).
Do you have Hide in Shadows? (attack, hide, heal if required, re-position, and repeat)
You could temporarily lower the difficulty in the settings, if you are not already playing on easy.
There are a couple statues or levers on pedestals which will lower a couple platforms in front of the hallway leading outside. I don't recall how many of the abominations use magic, but standing on the platforms would give you a good vantage point to use your bow. If the magic users are far enough away it should be possible to avoid the attacks, or you may be able to use the platform itself to block them.
BTW on the second platform you can hit a button on the wall to drop some loot hanging on chains from the ceiling, but you can only choose one. You may want to look around before picking one of the 4 nearby pieces of equipment...
