Allison, treasure those patches of sunlight as much as you can -- use them to accomplish what you can't when your grief overwhelms you. I remember those days, going from blackest impossibility to occasional bits of grey that allowed me to cope with the responsibilities I had.
I used to think that those little patches of light were gifs from my daughter, who couldn't bear to see me suffering so much. Possibly Byron is sending them to you, lightening the burden just a bit at times. They are truly blessed little intervals.