I read through the comments and thought that perhaps the following would work for you:
Wake when you need to (some of us are not morning people and need to sleep in a bit later than others!) - spend some quiet time reading the Bible yourself and get ready for the day
Put something in the crockpot or prep for an easy dinner (grill chicken for a salad, cut up the veggies or meats you'll need, etc)
School with the kids - lunch and snack when appropriate
Chores - do some training with them and some chores on your own while they play
Off to the gym. Get there right at 4 when the childcare opens. Use car time to listen to audio books, narrate, Spanish DVDs, etc. Lots of free resources on the web and at the library.
Get home and eat dinner. Clean up and get ready for bed. Computer time when they're in bed. I hate that rule but it's necessary for me. I get sucked into the black hole of the internet.
Do it all again the next day!
You're going to the gym M/W/F? On those days you can do crockpot meals or simple dinners that are cooked in under 30 minutes. There are tons of ideas for freezer crockpot cooking - prep meals in bags/containers and then when you need them toss them in the crockpot. Lots of ladies say an hour or two can prep several weeks worth of meals. Perhaps have lunch a bit later in the day so that dinner at 6/6:30 isn't hard. Or a late snack.
On a grander scale, spend some time decluttering and getting rid of junk. Organize. Perhaps you can set up a 4-day week with the 5th day being chores/cleaning/organizing for a while. Or a 3-week On, 1-week Off schedule where the Off week is cleaning/organizing/prepping meals for the coming weeks. Continue with the habit training for you and the kids. I'm the WORST with my own personal habits so I need lots of habit training.
I'm not a full-time single parent, but when my husband deploys I am. I find sanity in structure, schedules, decent bedtimes, healthy foods, exercise, and having a place for everything. The kids are much better able to help when they know what to expect, when and where to put stuff.
Hugs. it will get better.