Please help me and my puppy and senior dog afford a new AC unit in the excruciating summer heat!

I recently moved into a home after years of housing instability. Unfortunately, the AC unit is old and has been plagued with issues. My dad, who is a retired veteran, has sunk hundreds of dollars into fixing up this home for us and has hired professionals, but things keep popping up in the home. The most urgent issue is our AC unit. Currently, it is non-functional and the sweltering summer heat in Arizona is inescapable. I have a 2-year-old puppy and a 17-year-old senior dog, the latter of which overheats very easily. Please help if you can to assist in either repair of our old unit or a brand new one!