It sounds like a few things could be at play here:
1) You are spending so much energy and focus keeping it together for work, you are just all out by the weekend — spent. 12-hour shifts can be really tough.
2) Depression is back:
3) You haven’t found what is truly motivating to you yet, other than sleep and recharging for the coming week (which is ok). The ADHD brain is motivated by interest and urgency, not importance:
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism