So I'm a single mom of 2 girl, 1 teen and 1 little one (the teen lives elsewhere). I recently started working again after taking 3 years off, so during the week I'm very busy with my own school work, work, and the baby. I have no time for rest and I'm utterly exhausted. 

So usually I get to spend weekends with my teen, she really enjoys the time and I really do love seeing her, but lately I've been so exhausted and I lied about having to work the next few weekends so the teen can't come over and my baby stays at her aunts house. I feel bad about lying so we can't spend time together but I need time for me. I need time to be an adult and stress relief. 

Am I am asshole for this?