Employee with autism - what are my rights?

I have been working with the same company for years. I have been told today that even though I am capable of doing my work well, I was told I cannot get the promotion I wanted. This is due to my "disability" and problems with communication. I work in a busy office and am very straight forward and this tends to annoy people. I am sad because I work harder so they cannot use my autism as an excuse. I am very good with my job and have been told multiple times that I do a really good job. I am sad because it feels like I will never get promoted. I am autistic and will definitely have the condition for the rest of my life. Saying to me that I cannot get the promotion because I have issues with communication due to my autism means that I will never get promoted.

That's it. It is sad.