He is now in, he can't get out easily. Obviously he needs to negotiate, but its clear that the Russians need Crimea/Sevastopol, that's non-negotiable, and the Ukrainians didn't compromise, they even stopped the water supply for the Crimea.
The Russians demanded at least autonomy for the Donbass, but they never fulfilled the Minsk agreement and shelled the "republics" constantly, threatening to eliminate his allies by force.
Putin and basically all important Russian leaders said that a NATO membership for the Ukraine is thick red line, but the West never stopped to move forward in that direction. They even motivated the Ukrainians to go on with the provocations and not compromise with Russia.
I do understand the Ukrainian side, but the current borders are ethnically and historically artificial, basically wrong. It became part of the Ukraine very recently, with a transfer within the Soviet Union:
https://en.wikipedia.org/wiki/1954_transfer_of_Crimea
Crimea was always strategically extremely important and Sevastopol is the military and civilian door of the Russians to the Mediterranean. They can't give it up just like that, but the Ukraine never compromised and the sanctions didn't stop, while the water supply was blocked and this ruined the region.
The Ukraine need to, at least, compromise about Crimea and the West needs to aknowledge this. Of course, Russia might be forced to give this up and lose, but only by very brutal and very dangerous means. This is and always was insane. That the Ukraine could become a NATO member is bad enough, but with Crimea, that's just too much by any means. This cripples Russia for the future in a way which no Russian leader which cares for the future of his country could just accept without a fight.
Now Putin risked everything to force the Ukraine to a compromise, he is all-in. There needs to be a compromise with which Russia can live, or we don't know where the escalation might go. And I repeat that this would be a just thing, that the Ukraine in the current official borders, with the Crimean peninsula, could just join the NATO without Russian resistance is absurd.
Any Western state or leader which pushed the Ukraine in that direction must have known that this would escalate at some point, this was a wanted a conflict, nobody can be that stupid.