How do I fix my schedule so I can stop being so stressed?

I work 35-38 hours per week. I take 16 credits at school. I live on my own and pay most of my own bills, but I am still on my mom's medical insurance and she pays for school and my groceries. I am so beat. I am usually out of the house (including commute) 13 hours per day with school and work. Don't forget about getting ready in the morning and the bedtime routine. I would also like to hit the gym once in a while because I lost weight and need to put some muscle back on. I just don't know what to do. Please help