Mitsubishi Outlander Sport 2015 2.0 engine - low RPMs (so low it's about to stall) only when running the A/C or heat fan.

Yes I acknowledge that I may need to find another garage but I want to ask a broader population of mechanics and get a general consensus.

The issue: when I run the fan in my car, heat or A/C it doesn't matter, my car drops to very low RPMs and seems like it's going to stall out. It shakes a bit like it's not getting enough fuel or something so I get scared and turn the fan off before it stalls.

I googled it a LOT. It could be so many things, electrical maybe? Air filter? (My garage just said probably not the air filter without checking it) Battery? It gets fuel and doesn't have any low RPMs when the fan is off, it only has issues when running the fan.

Disclaimer, I'm not a mechanic, my family doesn't have any mechanics, and I have no idea how the fuel/RPMs connect to electrical stuff. If you need more info I can give it I just don't know what is relevant. Please help!