Op. not read all of this so apologies for repeats or to anyone I might contradict.
I was exeedingly work anxious and am diagnosed insomniac - however I manage it myself, been down the pills route and went very very strange.
I don't know your work or likliehood of doing anything about it so I'll stick to what you can control and thats your wn time.
I ride to and from work setting the day up (as best I can) going in and debriefing myself on the way home - even if I have to take a longer hiller route if its been a particularly busy one. It's a discipline that I had to learn and by the time I'm home now I have trouble telling the Mrs what I've been doing all day.
Also find a passion and a routine.
I've got outside interests that if anything now impinge into my work brain more that the other way round and my routine includes taking the dogs out for a brisk walk to get me in the mood for sleep in the evenings.
as for sleeplessness, the worst possible thing you can do is go to bed not ready to drop off & the more you lie awake in bed, the more you associate bed with not sleeping & the less you'll sleep there. Likewise don't drop off on the settee in the evening or you always will.
Don't go to bed until you're tired (for me when I'm in the grip of an insomniac phase this can sometimes be 7 in the evening; before my kids; sometimes 3+am for my alarm to go off at 5:45 regardless) but eventully you'll start to regulate to a set drowsy time under normal circumstances, you need to train and work with your body not against it to sleep.