Freelancers - how do you manage workload/scale when the work gets too much?

I've been working with a small marketing agency since 2022 - the work was mainly web design for local service businesses (wordpress/elementor) and subsequent maintenance, though this has sort of organically grown into managing google/meta ads for a number of the same clients too. It started as a nice side gig but recently the workload's exponentially crept up and I'm starting to feel stretched thin to the point my full time job's beginning to suffer and I'm trying to figure out how to keep clients happy without burning out. I've thought about bringing someone on to help with bits and pieces - maybe a junior freelancer who'd like some regular small projects - but I’ve had mixed experiences on Upwork and don't want to compromise quality. Has anyone here gone from being a one-person operation to bringing in help now and then? How did you handle it? * Do you give a percentage cut or pay per task/hour? * How do you vet people properly? * Do you keep client communication centralised or let freelancers speak directly with them? Appreciate this may seem like an odd question given there are so many other threads asking how to get more clients.