Can't switch off. Always restless.

Hi all I'm a male in my late 20s.

I don't smoke, I don't take illegal drugs and not on any prescription drugs at the moment, I drink alcohol once every 2 weeks. I drink a cup of coffee in the morning; I drink it for the taste rather than for the caffeine as it does nothing for me.
I exercise at the gym on a daily basis and I'm of a lean body mass with no physical problems.

Basically I suffer from alot of stress and depression due to my sensory disability. I've had surgery for sensory disability but it's not the best. But it's resulted in me having depression which led to my insomnia. I've had it since my late teens. Anti-depressants are out of the question as I've had bad reactions from them (I've tried many different types.).

I suffer from where I cannot sleep at all for 3 days straight or I can't seem to get more than 4 hours of sleep. It's severely affecting the quality of my life. I suffer from constant headaches, I'm always looking haggard and bloated and I often forget what I've done or said that morning due to me being so tired.
Every day is like living in a half asleep daze.

I work full time, and I exercise at the gym after work. At night, my body is physically tired...but my brain isn't. It's just so restless and I cannot switch off. It takes me a long time to switch off because my brain is so restless. I'm constantly thinking of the most trivial of things.

I go to bed at 23:30 and can't sleep until 3-4am then I have to be up for work at 7am!

I avoid television at night, I avoid caffeine/stimulants in the afternoon, I avoid bright lights as I know the emit blue light as they can disrupt sleep. I can read a book for hours without feeling tired.

I've tried sleep medication such as zolpidem and zopicone. I've had a bad experience with zolpidem so I avoid it.

Zopicone does work but if I take it more than 3 days...I've built up a tolerance to it and it gives me the severe hangover feeling the next day. So taking it every day is not feasible for me. 6 months ago I was addicted to zopicone and I don't want that to happen again.

Is there anything I can do to improve the quality of my life?

Many thanks.

Is it at all possible to go to the gym in the morning? I wonder if you're "getting pumped" there in the evening. And that you're sensitive to that so that it hasn't worn off by the time you sleep.

Does white noise or ASMR help at all? [This sort of thing... https://www.youtube.com/watch?v=_qscmiLap-g Just the first search hit, no specific recommendation.]

I go through the odd cycles of insomnia where I can't sleep well at all for several nights in a row up to about a week long. Longest was a 2 week stretch. My brain won't switch off during those times, it's usually when I'm anxious or excited/worked up about something it will hit.

I've found ASMR works really well when I remember to use it. I don't get insomnia enough that it's something I even think about it, I actually came in here just now looking for some ideas and saw Ada suggest ASMR to you and I remembered it works great for me. Totally worth giving a try!