I'm on the [autism spectrum][1]. My manager knows about that but my coworkers don't. 

I have been working here for a little more than a year and not telling my coworkers that I'm on the spectrum is really becoming a burden for me. I feel like I'm stuck in a big, dark, dusty closet and that I'm a liar and a fraud. This is really taking a toll on my mental health and that's why I have decided to tell some of my coworkers about it.

I'm planning to tell my coworkers individually and probably by writing (via an email or something). However, there is one big issue.

I already told people in the past that I was on the autism spectrum, but it very rarely goes well. Most of the time, people just didn't believe me. They told me that I "[don't look autistic](https://interpersonal.stackexchange.com/q/20696/21067)" and dismiss how being on the spectrum might negatively affects my life.

I don't want people to think that I'm a liar who is just seeking attention, or that I'm just joking. Especially, since I'm coming out to coworkers, I can't take the risk of people thinking bad things about me (but I still wish to disclose my autism).

So, **how can I disclose my autism in a way that people will take seriously? How can I mitigate the risk of them not believing me?**

###Notes and clarifications:

 - Due to my autism, I can't work full time (I'm currently working 75% after starting at 100% at this job) and I have an official "handicap worker recognition" in my country. 

 - I just want to be able to say "I'm on the autism spectrum". Nothing more.


  [1]: https://en.wikipedia.org/wiki/Autism_spectrum