He's the right age for a midlife crisis and a lot at that point can get triggered by growing mortality combined with a perceived lack of accomplishment in life. Additionally, as others have said, substance abuse is likely a factor in his life. A lot of wealthy people have huge substance abuse issues that their access to vast resources allows them to buffer most of the usual consequences of such. On top of all of that, he's going through a divorce and child custody case with Grimes that is gearing up to be more toxic than a bottle of freshly pumped reactor four coolant water from the Chernobyl disaster.

Yeah I think mental breakdown is a pretty good bet. It is highly likely Musk has a substance abuse issue on top of all of that which is likely not helping anything. The wealthy in the United States do have some of the highest substance abuse rates because for many of them, their lifestyles and access to their vast wealth helps to buffer pretty much a lot of the usual consequences that people face with substance abuse issues. It wouldn't surprise me the least to hear Musk diagnosed with oppositional defiant disorder and that he's largely avoided his "come to Jesus" moment in that due to his vast wealth.

the way hes talking is weird

Yeah, it looks exactly the same way my Aunt used to talk when she was heavy on psychedelics, including the body language. It's a kind of disinhibition where the mind isn't firing any of the parts that would usually guide a person on making thoughtful responses and keeping up with the current situation. Like Musk in the video constantly looks like he's talking to someone out in the audience rather than responding to the person asking the questions but then after talking jets his head right back to the person asking questions like he's asking "more fuel please".

I would be surprised if all of this isn't driven by some substance abuse. But that said, none of anything that's happening is likely good for his mental state, even with his wealth all of this is likely taking a toll on his mental state. The drugs only beg the question of how aware he might be of his declining mental health. But he'd likely tell any doctor concerned about Musk's mental state to go fuck themselves at this point.