he's not necessarily mentally ill, he's just mental. and extremely uneducated.
and to be sure, it's because of the way his life went.
he had literally everything handed to him since birth, rich parent, unlimited chances to make something of himself with his parents millions without a speck of fear of not being able to make it, he more than likely had his diplomas bought for him too, not to forget, his fathers name and business contacts. everything to allow him to be successful and still he managed to fail so many things in his lifetime.
yet, at the same time, he made a huge point of propping himself up as a larger than life figure that never failed anything. he's probably the biggest believer in his own lies, if he speakes it, it becomes truth, at least for him and anyone willing to listen.
and that's his entire existence. the man could not admit failure if his life depended on it. he could not distinguish truth from lie on any other measure than what he believes in or doesn't.
and while that could make for a headstrong person willing to follow through on his principles, he's laughably easily manipulated by anyone willing to suck up to him, like that entire fox news network currently does. they have is devoted attention and could tell him the moon has an endless supply of cheese and since the us flag is stuck in it, it rightfully belongs to them and he'd go out and tweet about tarifing cheese from switzerland.
they could tell him that the 2020 elections have been pulled forward to last weekend and that trump won in a landslide and he'd go and write a speech telling of his unprecedented victory. no one ever won two elections this quickly! can you believe it? i believe it!
he's still boasting about his 50% rating by the most right-leaning poll in the nation. probably believing that, as in grade school, 50% is a passable grade.
he managed to stunt an 8 year upwards economic trend. granted, he did somewhat kickstart some growth because of all his promises, but you really don't want to kickstart economies on nothing but hot air.
he managed to slow down job growth. and despite it all, he tries to take credit because he happened to be in office when those ongoing trends reached record levels. and not just once, since they were ongoing, they reached a new record periodically and he was whining for the credit on a weekly basis.
he gave money to the rich, no take backsies, and is making up for it by taking from the poor within 2 years with taxes, and was trying to take it back almost instantly with his attempts to remove what little support system the government offers to the poor.
he already wasted expensive missles on 3 attacks, none of which destroyed anything of value, just because an investigation, which he believes firmly could not possibly bring anything bad to light, since he has NEVER done anything bad, is ongoing.
and don't get me started on the constant transparent attempts to denounce anyone opposing him in the most childish way possible.
what I'm saying is, GWB was a better, more stable president than he was. and I'm talking about the parody version from That's my Bush here.
Or others 
