Hi VeryTired and Welcome!
Chutz said it well- and you "are" doing alot! Homeschooling your children, online college courses and raising 4 boys! I have two sons, one is grown and one is at home and is 17 and between him and the household that keeps me hopping!
And housework (chores) is highly overrated- I would gladly give up the chores around here if I could. Teenagers are not alot of help, at least mine isn't unless asked and then prodded a 100 times! The plus side to the children helping is they will become quite the self-sufficient adults when they grow up.
Having a good support group to come to, where everyone understands makes a difference in how I feel also. I was nervous about jumping on, and they could not be a more warm or caring group. If I am not here for a few days, I go through withdrawals, they have become like family. Give it a try and see if you notice a difference- we do care! And it was nice to meet you!