@caitlinr70637941 at MICA, greetings from a neighbor (and accessibility expert) in Takoma Park!
Love the graphic!
But anything and everything you create in Photoshop will be 100% inaccessible to all assistive technologies. Doesn't matter about layers or how you make the PDF or other exported file format.
Photoshop makes graphics, not accessible layouts. Plus there isn't one shred of accessibility in Photoshop for you to be able to make the graphic accessible. Only InDesign in the CS group of graphic design programs has the tools to make the final PDF accessible.
Consider your target audience -- students with disabilities that need to know how to get MICA's help at the disabilities resource center.
Putting the critical information they need into a graphic and its Alt-Text is a failure of the accessibility standards. The most critical info, such as the website, email, and location of the office, is buried in the graphic's Alt-text -- where it's non-navigable. That means the student won't be able to click the hyperlinks to the URL and email and get in touch with the resources office. (Think about the philosophical irony of this: a student with disabilities can't get in touch with the disabilities office for assistance!)
There are many ways to correct the accessibility problems, but too many to discuss here. Contact me off list and I can coach you through correcting the accessibility. I think you can do so through the Adobe system, but if not reach out to me via my studio's website, www.PubCom.com Would love to work with my MICA friends on this.