Ptrain

I've been having an issue with my 95 skyline gts25t being very hard to start and when it does start it has a really rough idle. It came out of nowhere. Today when I started the car up it was billowing smoke out of the exhaust and leaking a lot of oil.

The oil looks like it's coming from in between the head and the exhaust manifold right at cylinder 6? I'm pretty sure the oil isn't leaking from the valve cover. And I can clearly see bubbling coming from where the exhaust manifold gasket would be.

Also, am I missing an exhaust manifold gasket stud? The car is 100% stock so it would be weird for someone to have messed with the mani.

Here's a video with the engine running. Any thoughts?
https://imgur.com/a/2BiYWYU