When the children were young, my sewing almost entirely was made up of making clothes curtains etc and a huge basket of mending which I used to do in front of TV in the evening with my feet up!! I also had to work on the kitchen table, no other space was available to me. I also worked part time.
Now that the kids have grown up I find I have more time to myself, I have the spare room to spread out a bit and leave my work out. My priorities changed once the kids left home.
I have also found that when you are tired is not a good time to begin new projects and that with any creative hobby you have peeks of creativity and troughs of down time, that is the very nature of being a creative person.
If I am too tired to actually sew I like to tidy my work space and set things up for when I can get back to my sewing machine. I am also not a fast sewer so my output is not the same as other people, do not be so hard on yourself that is what I am saying, we are all different!
Gal