Waiting a long time, now things are starting to get difficult

I was given a basic assessment for Autism just over 2 years ago and I've been waiting for the full assessment all that time. Only when I queried the wait was I told "sorry, it can be up to a four year wait". On reading the recent NAS article, waiting lists are bad, but I didn't think they were that dire! I'm really struggling at the moment. The mental health support I received was a piece of paper with helpful hints to cheer me up (brushing my hair, for example!). I was struggling when I first approached the service 27 months ago, but then a year ago my manager went off work and I took on her role as well as mine. I have had rudimentary support due to funding, and my colleagues have worked twice as hard to support me, for which I am eternally grateful, but we are now all so fatigued.

I have not disclosed my autism because of stigma. There are 2 other staff members across our business with autism, both very different personalities, but both have experienced a mixture of kindness and prejudice. I disclosed my autism to 2 of my managers hoping for more support. The reaction was one of cynicism. I'm 46 - I have been perfecting masking for decades. I have refrained from telling them how I've been having to find dark places around work to disappear to when things get too much. If you're seeming to cope, you can't possibly be autistic; but if you do something a bit unusual because you need to try and manage your stress, then you're deemed totally incapable. This is my feeling, and for me it's confirmed by the experiences of my two colleagues and of my friend who is also autistic. It's stupid that I need a piece of paper to prove to my manager that I have a condition - but I'd rather do that, then wait until I have a full melt down, which I feel I might do.