Chemo brain

Chemo brain is very real.  I didn't work during chemo but went back shortly after and I struggled.  Nearly 2 years later it's better, but not gone - whether that's because it's improved or I have gotten better at managing it, I'm not sure but there's still major holes in my memory and if people keep interrupting me, I have no idea what I am doing.  What you're describing is really hard as being constantly distracted means you can neither write things done nor be mindful about what you are doing.  I don't know what your job is, but is there any way you can hold calls until you have finished something?  If not, rather than answer on the second ring, maybe you could leave it long enough to write a "placeholder" post it for your file - some word or two that will take you back to the point (or maybe pre-write some code words to grab if that's suitable).  I don't know what may work for you but it's worth exploring different options.  (BTW - my kids still laugh at me)