I am in a similar situation. I also have two children who are 17 years and 11 months old. I go directly from work to the gym at least three days per week, so I don't even see them until close to 7pm.
I don't worry as much about leaving the older one because she is up later and I can interact with her later in the evening but the baby goes to bed at 7:30pm. On gym days I come home, feed him and put him to bed. I try to take comfort in the fact that they are with their dad. One on one time with dad is important too.
I also know that I am happier, sleep better at night and more energetic to take care of household responsibilities when I am working out regularly. That "me" time is important for my sanity which ultimately benefits the kids.
"If it is to be, it is up to me."
| current weight: 176.2