Chronic Fatigue?

Hi everyone,

I am new to the community, but wanted to join to seek advice and help from fellow spectrum dweller. :-)

For a number of years now, I have been experiencing chronic fatigue that is debilitating (to say the least). When I wake up in the morning, I feel okay at first, but within two-to-three hours I literally have to retreat to bed, where I end up sleeping for another two to three hours (and I mean sleep! Completely unconscious). I've tried everything—changed my diet completely (I am vegan now), quit drinking alcohol (almost five years ago), exercised regularly (walking), fought hard not to nap during the day (which doesn't make it easier to sleep on an evening). Nothing seems to help. I'm just completely wrecked all the time. Today, I am hardly able to walk without feeling exhausted to the point of collapsing (or collapsing in bed, which is what I'm about to do now). 

I've read a lot of material on autistic burnout and fatigue, but to be honest, this isn't a 'phase'—it's something more permanent, it seems. 

Has/ does anyone else experience fatigue of this nature? Is my story familiar to anyone? As with most things, I'm trying to understand if it's all 'in my head,' or if my experience is common among autistic folk. 

I'd appreciate any discussion. I'm at my wits end and don't know how I can carry on in the manner. I can't work full days any longer and have just returned from sick leave after two month off. I have only returned because of the guilt and shame that I feel. I love my job, but the body doesn't seem to want to play!

Thank for taking the time to read this. I'm desperate at this juncture :-(

All the best

Billy