[lsj0627]

I'm in a similar situation:

You're super fortunate in that you at least have those short-term "best programmer" phases (especially in an industry with high pay and high demand for your skills).

My advice: use your ability to make yourself indispensable. Then you can lay out the terms and call the shots.

I use excuses for my long term absences because the stigma of my severe mental illness is too high. But if you perform well and deliver as promised, it doesn't even have to come up...

As far as explaining away the need for long absences, I personally keep it simple and vague, and Positive: that experience has taught you that you're happiest and most productive working on this bizarre schedule. It can even create a little "eccentric genius" aura and the illusion of confidence. Just be careful not to take this too far and enter jerk territory. They're still going out of their way for you, so gratitude & humility are important.

I'm very sorry to hear what you're going through. I understand it and it's incredibly difficult, but really admire that you're looking for ways to fight and work throughout it.