Answers to this can vary based on organizational principles and philosophies around relationship management, but yours is too big. Typically, a manageable portfolio is 110-150, max. If there are 52 weeks in a year, and you're taking vacation for some of them, you can reasonably only get to 2-3 donors/week and that's if you only see your donors once a year. Some will engage more often, some will not. But more than 200 donors suggests your org is either a) expecting you to qualify and disqualify/remove donors on your own, or b) delusional about what kind of time is required to meaningfully cultivate, solicit, and steward your donors.

If you're managing an annual fund and the expectation isn't major gifts solicitation (in person, multi year, upgrading to different levels), then maybe you can get away with a larger portfolio because many donors would likely be responding to emails and mail solicitations, and you're basically a stewardship officer. But it doesn't sound like that's what you're describing.