Because you now did it to yourself.
I would be more concerned if he were less stupid. Going by his last presidency he’ll spend half his time golfing and the rest driving through ineffective “red meat” policies to get attention from his base. Ultimately he’s just a pathetic man who craves attention.
What concerns me more is that his destruction of political norms means that someone who is similarly evil - but actually capable - might be able to use him as a template to take power in the future and make America into a dictatorship. Someone like Xi Jinping as opposed to an aging B-list celebrity.
You should be concerned regardless. He is backed by considerably smarter people whose agenda is way worse than last time. Regardless if Trump pays attention or not the worst people will be unhindered. He isn’t even a blocking element to those people taking power because Trump is at worst a rubber stamp and more likely a corpse given his age and lifestyle.
Short version, there isn’t even a remote, barely visible silver lining.