Some things you missed
his mom already died, after the Jedi forbade him visiting or protecting her
he was a fatherless slave boy so already deep rooted insecurities regarding control and safety
He wasn't allowed to publicly love or protect Padme either
the council weren't friendly to him at all, only Obi Wan. They treated him like an outsider even after years of loyal service in war, and even turning over Palpatine himself.
finally
all of these fears, insecurites, and premonitions culminate in a heated moment where Mace tries to extrajudicially execute the chancellor without a trial, confirming Palpatine's claims that they were out of control and power hungry
From there, obviously, things happen too quickly, be it adrenaline, force intoxication, whatsoever, he is taken over by a mist like a berserker. But there was tons of buildup that you apparently missed. You haughtily assume he can see the future like you can, since you watched the OT already, he can't, and contextually speaking the Jedi are not his friends, are not helping him, and look power hungry and crazy too.