The dragon and human experience points are common; if you could level in human form your dragon would be stronger. Perhaps you could level in Keara's fortress (using the spawning opponents in the outer headquarters section), if you have a save before then and don't mind redoing the end of the game.
Level 34 is about average for the end of the game; I got to level 36 without trying too hard (I delayed going to sentinel island so I could level and get the best effect from the level-up bonus mindreading the island in the first encounter, and put a few points into Wisdom, though mostly from equipment bonuses). To get above 37 I think you would have to spend time in Keara's fortress or the ministry with spawning opponents.
The add-on is adjusting the combat mechanics so they are not so strongly level dependent. If you can not get through that section with a different technique, or spamming potions (I believe you can use a rejuvenation potion while waiting for the healing potion cooldown), and are not going to start a new character anyway, you could just hang on to a save before entering the Hall of Echoes, and see if it is any easier with the add-on / next patch.
