My energy bill makes no sense.

I’m not sure where else to post this so if there’s a better sub you recommend let me know. I just need help/ advice as I’m unsure what to do. I live in a 650 sqft apartment in texas and my energy usage is so insane that it makes no sense to me. This past month i’ve somehow used 1100 KWH, and the previous month was 730 KWH. I keep my ac around 70-74 when i’m home and when i leave i turn it to 76. If i leave the house and i know I’ll be gone until its dark out i will leave ONE lamp on for my cats. That is most days, I work full time for context. Whenever I am home i will have maybe a few lamps on, i rarely ever use overhead lighting, and I do watch tv most nights. Where is this coming from?? I just moved into this apartment. It is a little bit of an older building. I have emailed my landlord because i think the cause is my AC. Whenever i first moved in the AC broke after a few days and wasnt running cold air at all. The AC tech said that the thermostat I have sucks. Ever since my AC has been fixed i notice that the fan runs VERY often, I have it set to “off”. I understand that it will come on from time to time but it comes on very often and will stay on for a long time. My landlords response to my email was to tell me to get a window unit. He has literally been no help. Why is my bill so high???