This will sound dumb, but I'm saying it sincerely.
I've had similar issues (without getting into details), but what worked for me was getting outside a couple times a week. By that I mean bringing a tent or hammock + tarp and sleeping outside a couple nights a week on workdays.
To be specific: I sleep outside Monday-Tuesday and Wednesday-Thursday. On those days I also make my dinner at my campsite. What I've found is that my brain goes into a much more "primal" state of "monke outside in cold, monke get shit done", and that it propagates into my day and week.
The barrier to this is of course actually going outside, but I've been able to get to a place where I have a "deal with myself" about those two nights a week. I always have my pack ready, so it's just about grabbing it and heading out- I think that's key.
I'm not saying this is a solution for everyone, but it's done wonders for me. As of now, I get restless and feel bad if I'm in a situation where I can't get outside at least once a week. It brings me a peace of mind and will to get stuff done that nothing else can.