It is difficult to fit in when you have a child at home to take care of like you do. Is there anyone you can trade childcare with so you can exercise?
My situation is that I have 2 children who are both now in school, with my youngest just having started Kindergarten this past Sept. I work at home about 5 hours a day doing medical transcription and I volunteer at the school a lot. I also, of course, have housework, grocery shopping, etc., etc.
What I do is drop my children off at school and head to a local walking spot around a pond and meet up with a friend & walk 4 miles about 4 days a week. It takes me about 50 minutes. Then I go home, shower, and start working, then I have about 45 minutes to clean, then I go pick up the children and help with homework, etc., cook dinner, clean some more after they go to bed, laundry, etc.
I usually try to get in 7 miles on the weekend. Either my husband watches the kids or I trade off with a friend. The friends may not be walkers, but they do like to run errands by themselves,etc.
When my children were out for the holidays it was harder to fit it in, but I did. I made it a priority in my life because I felt like I was physically falling apart. I felt guilty at first for taking the time for myself, but then I have realized it is benefitting everyone because I have more energy and I am becoming more healthy. It just has to be a priority.
Best wishes to you!!