Why is my energy bill so high every month?

Trying to gain some insight and hopefully come up with a solution to my high energy bills. I’m currently living in the Houston area in a 2 bdrm apt and my energy bill averages ~$160 a month or so (summer time should be fun) I’m using TXU & usually keep a/c off as much as possible during the day (on for a couple of hours while toddler naps) and typically have it at 70° at night. Water heating seems to attribute to a decent amount of usage as well. Is this a normal bill amount? Should i get maintanence to service my unit? Risk of mold while having a/c unit off during most of the day? Educated insight is MUCH appreciated. (Switched to free night as of 5/9, so we’re trying to center most usage in that time frame) TIA!