At first my car would die on me by pushing
the break now it dies on me when I turn up
the heat or a/c what could be causing this?
It sounds like a short in the accessory panel or otherwise some where in the dash. You could be using the wrong fuse in a slot so I would start checking there. Being breaks and heater it could be the heater fan switch, the break light lines, or (much less likely) a short in the master cylinder pump which would engage with the breaks. Your best bet would be to see a mechanic and describe the problem since electrical work can be dangerous and a mechanic may have a tool that better assists in finding the problem.