Buffering with shopping

Every saturday, start of the weekend and free time, I am generally feeling overwhelemed by all the tasks I could and would like to do. It all piles up like a giant to do list.
I generally start with the market for food shopping. On that market street there are lots of charity shops. I end up browsing and spending a lot of time shopping for clothes. If I buy somehting, it will need to be washed and mended, more time.
That routine makes me late on all the other things, like preparing lunch for the family, putting my house and life in order, spending time with my kids. The result is I get mad at myself and exhausted.
How can I get out of that circle?