I can say with certainty that your original AF gear, with a level 40-45 weapon will end in failure. The weapon is the most important for all classes, including healing, and you don't realize just how much it adds until you go from using a level 40 staff and Cure 1 doing 500, to switching it for a level 50 weapon and having cure 1 do 700. Not to mention the increases to the rest of your healing spells.

Now a decent level 50 weapon with your AF gear isn't too bad for AK. The DPS may struggle a bit here and there, but for the most part you should manage to squeeze by. However if you are having troubles, go back to Wanderers Palace and farm that for a bit. The gear is literally 5 Item Levels below that of AK. Or you could run the 8 man dungeons for the storyline again and just stock up on Philosophy stones and buy some gear from the vendors with it. I personally started with the jewelry, as it was my biggest upgrade at the time.