Low Damage?

I have a Lv 150 ranger, on her fourth rebirth, and her atk in the char window is 70k but she deals 8k damage to Mouzers??
Previous rebirths she would do 40k even with the large level difference, it seems like with every rebirth, her damage is dropping? It's getting very hard to level. I even activated all the buffs and pots, I cannot find an explanation.   I even use donor weapon..