whats wrong with my car?

[eastcoastS14]

Ok so lately my engine has started making a lot of noise....specifically it sounds like there is an egg timer under my hood. It has been doing this since I got my headgasket replaced which had me thinking it was the top timing chain tensioner maybe? Also my idle bounces around A LOT usually after the engines been under load and I stop at a light or something, strangely it gets even worse when I cut the wheel all the way. I cut the wheel to park the other day and the car stalled which was a first....I was thinking maybe the IACV but i dont understand why it stalled when i cut the wheel. as the idle bounces usually between 500-1k rpms the lights dim in and out so alternator maybe? anyway heres videos of my bouncing idle if that helps