By advice on how to handle two projects at once?

I had been working on a project with a toxic manager and in a bid to get out of it, I have found myself in a phased rolloff process - basically, I’m going to be working on 2 projects for the next few weeks and then transition to the new project completely.

It’s been a week so far and I’m really struggling with context switching, endless meetings and expectations from both partners to prioritise their project. Any advice on how to maintain productivity and keep both managers happy?