Ukraine territory is undefendable, especially in an era with satellites and drones. Russia has far more people who seem more willing to fight than their Ukrainian counterparts.
Even if Zelensky can get NATO to send more money/arms, who will there be left to deploy it to the battlefield?
The only hope for Ukraine is NATO formally entering the war, but that could eventually lead to WWIII. Also, it appears that NATO may now be a paper tiger as they all claim that their stocks of arms have been depleted by what they have already handed over to Ukraine. Since the West has chosen Finance over Manufacturing, our ability to restock pales in comparison to Russia's. The longer a NATO v Russia war lasts, the better it will be for Russia.
If the Americans actually fight the Russians in Ukraine, it will be like the Persian Gulf War.
But it won't happen because Putin will nuke us at that point.