My prescription for the blues:
1) Think: The shortest day of the year was yesterday. Every day gets a little longer with a little more sunshine!
2) Do this: Follow the sun around the house during the day. Eat breakfast in a sunny window. Walk to the mailbox during the sunniest part of the day. Have an afternoon coffee break in whichever window is now sunniest. Enjoy the beautiful sunset no matter how early. Lack of sunlight can literally cause depression. Make yourself mindful of the sun and enjoy every day as it gets a little longer.
3) Do this: Go drive around and look at the Christmas lights after the sun has gone down. This is the reason that people have celebrated with lights during the darkest time of the year throughout the centuries. We feel crappy in the dark and more joyful in the sunlight. Funnily enough, this was even allowed when we were growing up JW. And it was normally during the drives to and from the meetings that we looked and oohed and ahhed!
4) Remember this: You did the best you could with what you had at the time. Forgive yourself for the way you raised your kids. Regret will eat you up. Consider having an honest talk with your son about this. I'll bet he would be most forgiving. At the least, you could figure out how to make amends. But, I really empathize with wanting to keep giving your kids everything. Mine is in college and is struggling which is its own burden. We're considering having him take out student loans. I'm still worried about his future career. Keep in mind, though, that the greater gift at this point is that the kids shouldn't be burdened with taking care of their parents in their old age. Keeping yourself solvent IS a gift. Hard medicine for me, too.
5) Do this: Spend time playing with your pets if you have them. They aren't burdened by the past or worried about the future. They love you unconditionally right now, and you are the greatest person in the world to them!
Best of luck,