Stalling with heat or air on
Maybe the idle air control is not increasing the idle for the added load of turning on the blower motor.
Hello there. When this started, I'm betting the battery was disconnected for whatever reason. Will happen if AC or defroster is on. Cheap fix, remove fuses # 10 and #28 under the hood. Then remove your throttle body, and clean it with a sensor safe spray like Seafoam, clean with soft bristle brush and a rag. Put back together, done.