Sunset duo just hang and I love it.
You know when his eyes get all round? Yeah, I love that too.
Okay, the farmhouse ark was awesome, and well done. It was beautiful.
I think something hard to show was just how much pressure was put on Donnie at the time. First off, he blamed himself for Leo's comatose state, because he didn't want to leave the lair. No doubt he was beating himself up over that constantly (also his father "died" and he might have blamed that on himslef too). And he's also the default medic: everyone would have been looking to him for how to treat Leo, even if he had no idea how.
That's a lot to put on a guy who's just lost everything he ever knew, all his tools, two members of his family, his hometown, and probably has no internet connection to boot. Raph was keeping watch over Leo and wrapping his head around being temporarily in charge. Mikey was distracting himself with chores and activities, trying to keep everybody going.
With no recources to speak of and no one who could help.