We have been wanting to place him in music lessons and a martial art, but the time structure he's been locked into has been prohibitive.
Along with all the excellent suggestions and support above, I suggest that you implement music lessons and martial arts into his schedule for multiple reasons - his own enrichment as well as decompression time and a break for you. For music lessons, if he is old enough to handle his daily practice with just a little oversight from you, that could be time that you spend on your own. Many music teachers are so busy in the evenings when public schools let out - so, it would be very easy for you to get a great teacher because of the flexible schedule that you will have.
And martial arts is not only an excellent sport, it is also great in instilling self-confidence and self-esteem. You can either drop your son off at martial arts or you can join him in the classes.
I think that you can incorporate a lot of such activities in his schedule to make time for you to decompress, get alone time and also to do things with your son if you would like to.
