That is terrific that you have wonderful family for support @NelSky ... and great that you are maintaining your yoga & art - and riding the waves - I am jealous!  These things all require concentration & will take your mind off your current issues - I run a ukulele group & also fish a lot from my kayak, so I made sure I did this as often as I could & it really helped me.
I found it was  mainly at night that my mind went haywire - but it DOES settle down eventually!  Definitely Try Slow Deep Breathing when you get upset .... it can help calm the heart beat & just regulate things again xx  
Try not to overthink everything - difficult tho it is.  Just take one day at a time, try & get out & do things with your son, so he doesn't miss out - he will be very worried for your welfare as well!!  There are organisations that have programs for teenagers who's parents are undergoing treatment .... I'll try & find some details - he may benefit from this!  xx