[tdfx]

I highly recommend Notion for building a knowledge base at your organization. We have one section dedicated to company-wide knowledge, and another section dedicated to various tasks. Any recurring task should be documented fully, with screenshots or a screen recording. The upfront time investment of doing this allows you to really let go of the burdensome stuff. For any work that isn't creative or specialized, you really shouldn't do it yourself longer than it takes to document and delegate it.

Once you've got the workflow in place, finding an assistant is really just a process of elimination. You can easily find someone with C1 English skills for less than $10/hour on Upwork.

You'll need to filter through a bunch of bad ones to get to a good one, but again, this is an upfront time investment. Establish expectations early and fire quickly at the first sign of issues. Trying to "make it work" is worse than accidentally losing a good candidate.

I would also encourage you to post it as a full-time position, as you don't want to be competing with other clients (you still will, but if you're their primary professional focus that pays the rent, you won't lose out in most deadline situations).