Hi,
I'm in the same situation, and it's tough. I do have joint custody with my sons father so he has him half the week and I have him the other, but between work, school and physical therapy 3 times a week (I suffer from chronic migraines)I'm just wiped out. My only real full day with my son is Sundays (he is 2). I don't do anything but play with him on Sunday, we will watch the same movie 4 times in a row if that's what he wants. I take him to the park to ride his bike, we build towers with blocks and it's the best day of the week =) I have also just started doing our Friday morning breakfasts. Every Friday, we go and get special dougnuts (they are special cause that's the only day he gets them), coffee (for me, he gets chocolate milk lol) and we throw pennies into a fountain. We decorated a jar for his pennies that he earns through out the week for being a good boy, using his manners etc and on Fridays he can throw as few or all of them into the fountain, we have a great time. We do have to wake up a little earlier in the morning to do this but so worth it. If you could start to plan little things like that on Mondays when he gets out of school, both of you will be happier. I look forward to our special breakfasts together. Also, just taking 10-15 minutes every night to read a book before bed will let your son know that you are making time for him. Lastly a strict schedule and organization is the key, or at least for me it is. Every Sunday after I cut coupons, I make my list of what needs to get done through out the week (laundry, bills to pay, homework, work projects, grocery shopping etc), I then break it down into small, accomplishable (that is the main thing to remember) daily to do lists and stick to the lists. Every task has a day and it stays on that day. If you just keep a running tab of what needs to be done in your head you will feel very over loaded but breaking it down day by day and being able to cross things off the list every day realy makes you feel like you have accomplished something and lowers stress levels so that you don't wear yourself out. I hope this helps- if you ever need an ear to listen, please let me know.
Good luck and it will get better! =)
Take care,
H.