And it went GREAT!
I did a couple of interviews with Human Resource's disability expert first, to discuss what could be done to help me work better. I did some research and found that it's best to go in there with very specific requests. I came up with a list of things like "I'd like a mentor to help coach me on how to deal with difficult clients, tricky team situations, etc." or "I'd like to get changes in procedures in writing so I can be sure that I've understood them and refer back to them."
It's not actually required in the US to tell my boss what disability I have. Human Resources needs to know what the diagnosis is, and have the official documentation from the psychologist, but it was up to me to tell my supervisors. I thought it would be a good idea so they would have a more clear idea of what they were working with, and might help clarify issues I hadn't thought of. The list of requests seemed a bit random without the explanation.
My boss and her boss were there, and they were very supportive and great. It turns out that the senior boss has known some Asperger people already. We're still trying to figure out if there is a better way for me to track my project milestones and budget when I've got multiple projects going on (I'm a web designer, and I may have 2-3 large sites and a bunch of smaller projects going during our busy season, each in different stages).
I'm hopeful and feel a lot better about things. It's a big company that prides itself on supporting diversity, so I think that had a lot to do with it.
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Diagnosed Bipolar II in 2012, Autism spectrum disorder (moderate) & ADHD in 2015.