Ghosted? PI of >1 year not responding to emails for new mentor?
Go and visit your PI. Knock on their door when they're in, and ask them everything above.

You write in a comment above that you feel feel "kind of scared/awkward doing that since he has a very cold, direct manner". Being scared should not be a deal breaker. Courage comes when you overcome fear! It's much more admirable to face what you're afraid of than to hide from it. Nothing critical will happen to you, and to have done something like this before is a great help if you have to do it again in the future, in less protected environments. As for how others don't knock without a meeting, you could knock and start with "are you free?" If he says yes then you're good, if not then you can arrange a meeting.

Finally you write that you don't know what to say or how you'd react to a rejection, which shouldn't be a problem. For the first, write down everything you want to know, and rehearse it beforehand. For the latter, if you are rejected, you're going to know in the near future anyway, and you might as well know now so you can make plans for what to do next.

It's better to be addressing your problems than to sit around waiting for the PI to respond. Go and visit your PI.