2003 Ford Ranger Engine Problem

My check engine light was on a couple of days, then started blinking as I was sitting in park, and the air compressor started clicking on and off, and it felt like the engine was going to stall, which changed when I put it in gear and was driving.
My mechanic changed a hose he said was ripped, and too much air was getting to the engine (pvc hose?).

Now, while driving, it feels like i'm dragging something, or carryiing an extra load.
The idle is real low, and when I stop, in gear, the air conditioner compressor clicks on and clicks off quickly and constantly, until I get to driving again or put it in park.

Please help, because I can't afford letting them "figure out" whats wrong with my truck.
Thanks