Help us survive the Texas heat

I really need some help to get my air conditioner functioning better  so it isn’t running 24/7. I got home from work today and my house was 90 degrees and the dogs and Alyssa were miserable. I also need to replace my single Pane windows so the cold will actually stay in my house and the heat will stay out. Last summer my electric bill was coming in between $600-800 a month. I’m a single mom and I am already working full time and can not take on any more work hours. Another summer of bills like last summer will be more than I can do and I will loose the house or die of a heat stroke in here with no electricity. I have already got a 338.00 electric bill for last month and it wasn’t even hot yet. I’m scared and don’t know what else to do so I am tossing my pride to the side and asking for help.  The lowest estimate I got for replacing all my windows was for $7000 with window world. Thank you for reading this and thank you if you are able to help or share.