Am a project manager myself, always having multiple projects at any given time. I have blocks of activity in my outlook calendar. Catch-up on stuff that I didn't get done the previous week / new in my inbox that need immidiate attention on Monday mornings. Some meetings in the afternoon.
No-call Tuesdays, partly because I have my son at home in stead of daycare then, which allows me to do administration stuff. Wednesday I have half a day calls with customers/stakeholders for updates and such and half a day for actual work. Thursdays I have a lot of internal meetings, with colleagues and to optimize processes etc, which should lead to less pressure in the future. Fridays whatever needs doing / socializing.
I also have a 10-15 minute cal with my team everyday just to see what everyone is up to, if they need help etc (stand-up call).
Other than that, the difficult part is to have the discipline to do what you scheduled time for, also meaning telling people 'not now'.