All.i can say is don't think you can suddenly just get your house clean and decluttered in 1 day/week/month.
It takes time to change habits, and if you're lacking energy then you're not going to suddenly going to start cleaning before/after work.
Be realistic and start with small changes to your daily/weekly routine. Have a look into cleaning schedules and do one that works for you. Try not to clean your whole house in 1 day. However, the more you clean the quicker it becomes as there's less dirt/ clutter to get rid of.
As a minimum:
Wash bedding weekly (you may have to do your bed 1 week, then the kids bedding the following week).
Depending on the kids age get them in the bath together, use it as playtime and try to clean the toilet and sink. Try and wash the tub before they get in. Or wash the youngest first and the oldest can wash themselves in the same bath water. Ideally the bathroom should be cleaned once a week.
Pay for a car wash that includes the inside every 1-2 months.
When you do declutter, don't separate things to sell. Either donate or bin/tip to get rid of stuff quickly. I usually shove a bag of clothes in a clothes bin that's next to bottle banks, save me time of actually going to a charity shop.
Floors really need to be cleaned once a week minimum. For now maybe try once fortnightly.
Set certain tasks for certain days and stick with it. Tuesday- bathroom and kids bath. Wednesday- bedding. Fridays- floor.