Oops, I knew I’d left something important out… My reasoning was meant to be that - like you reading old and new studies regularly - I don’t see the scientific “why” being answered in my lifetime, and in any case not being answered now, altho I want to do something now. So I was comparing the philosophical why of life with the scientific why in that both are in a way out of reach. (The scientific causes of life are probably better known than the causes of fibro! 
That’s also why I was talking about making the ground less shaky by finding “causes” or at least help for single symptoms.
“putting something cold helps you. Is that right to say?”
Not quite that easy! 
Cold is poison to me as to most of us for a longer amount of time, as in staying outside in cold weather. Bathing my hands in cold canola in the rheum./fibro-clinic for 15mins. caused a big flare. But 3 mins. was quite OK, helped. And before that I’d already found out that 3’ whole body cryotherapy, which is propagated here by patient societies, and also 2’ showers or cold washing can alleviate pains and especially the Ache for quite some time. But “putting on” cold pads doesn’t, for longer I need heat. More details in the cryotherapy-link posted above Heat & Cold therapy - 6+1 types (Cryotherapy)
I understand the getting up early part. On a similar note, I once had the idea that 9h might be too much, so went back to 8.5h and 8h, and the Ache got worse. Now I’m going up from 9h to 10h and the energy is getting better. Also I know that before fibro I used to get headaches and didn’t at all like sleeping more than 8.5h, my average was 8h, and while working often 7-7.5 with no big problem. And I read that that is normal, there are studies that show, that sleeping too much gives you headache, just that it’s different for everyone how much. So it’s clearer in my case. I do remember that I started taking a sleep break for an hour, sleeping 2x4h. Finding that strange, my wife too, I looked up and read that that seems to have been perfectly normal in the 17th and 18th centuries!
So sleeping 12-7 at night is good for you, then working, then a light lunch, but that all makes a nap necessary, which you’d like to get under control, I think I’ve understood?
The usual main problem for fibro, apart from the sleeping problems, is of course to pace yourself with every activity, resting in time, looking for the invisibly moving sweet spots for everything you do. In my case I need an active break with certain exercises and cold washing after 1h of work in the sense of talking to people, better working from home. If I take the break in time, I can manage another hour and another. If I don’t, the flare comes immediately and may take a few days to calm down. So in your case I’d suggest taking active breaks breaks regularly, and each time try to get your body back down to zero. If what you notice is the “bitterness”, then try to find out if it’s enough to take an active break at 12, or if you have to do it before at 11. It’d be helpful to learn to sense what exactly comes along with the bitterness - is it fatigue in your limbs, for instance? Because bitterness alone doesn’t necessarily explain long sleep being necessary. But as long as you have nothing else to go by, then by all means use that as an indicator. Fibro means trying to NEVER do anything “on extension” as you put it, or if you do, you will definitely flare, so you have to calculate it well. We call it “overdoing it”. There are certain things, like cleaning windows, which I can only do for 1 min, other things for 3 mins, some for 1 or 2h (that’s usually the uppermost limit for anything I do). To still keep active longer, I switch tasks.
Now what about the 3-4h? If it’s so regular, your body seems to need it, doesn’t it? If it does then, when do you want to take them? Does it have to be in the daytime? To solve that, maybe you could try not to nap at all, all day, just take active breaks and try to stop the “bitterness”, i.e. the overdoing it, from building up. That way, you might be able to work in the afternoon as well, again with active breaks, and break down at 7pm, and then take the 3-4h. If I napped, I’d sleep. Some days I yawn a lot, feel very tired. But I don’t let myself sleep, so that I can sleep better at night. What happens when you try that? Having to sleep 10h per night and needing 1-2h additionally for that, plus feeling tired from 6pm on, means I am less productive - that’s fibro, there’s no way around that. Fibro is telling us we have to stop, because we believe productivity is more important than our body and fibro tells us our body is the requirement… It’s hard accepting that, but it’s a fight we lose, if not, because it’s the reality of fibro, the new reality of our lives…
What a quirk that I’ll have to try getting up at 6:30 or 7:30 on Thursdays after the lockdown and am now considering taking a 25 min. nap, which may then get to be 3-4h… JayCS’s Fibro Blog - #212 by JayCS (situation in the post before)… 