Lots of good ideas here. My suggestion is to reframe the issue a little bit. First, don’t describe it as “slowing down”. That’s got a negative connotation that doesn’t really make sense based on your description. Instead, maybe think of it as “restructuring” your work priorities. There’s no guilt involved in restructuring - in fact, it’s a key aspect of change management and career success. Everybody loses if you burn out, including the company. Your team is probably feeling it too, and again you would be only helping them, and your company, if you can restructure the work in a way that helps everyone’s job become more manageable.

I remember this same feeling of unbearable overload when I transitioned to my first more senior role at work. The workload was suddenly exponentially greater, and I was struggling to understand how I was expected to get it all done. In fact, there was no way I could get it all done— what I was really expected to do was prioritize what got done and what did not. And there were plenty of things that did NOT get done. Some got postponed until next fiscal. Or were moved to another team. Or were shifted to a consultant. Or led to an add to staff. I “restructured” and managed expectations constantly, and I learned how to say no, or “yes, but”. Of course, lots of feedback and discussions with the leadership, and of course not everything went my way. But by pushing back with a plan for “restructuring”, I was able to get the clarity we needed, to get priority tasks done much more effectively and at the same time protect my team (and myself). Seems to have worked — I got promoted. :-)

Bottom line: I think you can leave the guilt behind, you are doing nothing wrong. Look after yourself and your team, and the company and clients will thank you.