How can I reduce irritability, mental sides etc... for a more aggressive deficit?

I'm looking to lose weight and a 500 calorie deficit just doesn't seem to be moving anything. It may be a miscalculation issue. When I drop even lower, I get alot of hunger, but worse I get irritability, low mood etc... my energy to go to the gym plummets.

How can I go about losing the weight but not sufferimg the mental and emotional sides? The hunger I don't mind, I actually enjoy it in a way because it reminds me I'm on a deficit and moving in the right direction. But the low mood etc.. have been brutal to deal with.

Is there anything changes I can make like diet etc?