If your setting cam sensor code and it's running rough I'm going to assume it runs rough at idle and runs better off idle? If this is the case and changing oil fixed it, this could be an oil pressure issue. With the low oil pressure the phasers won't work properly. You need to have 25psi oil pressure minimum to each cylinder head. If it comes down to this point then there is no point of putting anymore money into it. You can try and flushing the oil system in case some debris got stuck in a passage. Also make sure you use OEM oil filter. I would call around and see if anyone would perform an oil pressure test on your vehicle when it's cold and when it's hot.

The AC concern if it is t switching from hot to cold I would suspect the temp blend door motor. The motors that work the HVAC doors tend to fail over time.