Okay! This is normal. Anyone who is working at full tilt all the time is going to collapse when they finally get a break. Everyone does this.
You arent lazy! If you were lazy would you have a responsible job, young child and household to manage? Did your 14 year old self have these responsibilities? So less hard on yourself please!
This is my strategy:
Plan at least half of your "time off" as a guilt free break, and allocate most of this time at the start. (Eg if I had 4 days, I would break down: 2 days guilt free relaxation, TV then 2 days tasks with 1 evening clear to unwind at the end).
Plan something to get you out of the house during your relaxation phase. This can help prevent the "stayed in bed all day and now I feel worse" phenomenon. Obviously some time just pure lazing may be needed to unwind but if you spend an entire day lazing you will feel more tired at the end of it. Spend some money if you've got it, or have fun with a friend! Something you usually "can't find time for". Just a walk or a swim or shopping trip (or whatever you enjoy but active is better) if you haven't planned anything in advance. If you have a romantic partner spend an evening on a date with them.
Then, plan small achievable chunks to get through. Realistic is better, but if you're a perpetual optimist and overestimate what you can do - remember at the end to focus on what you have achieved, not what's still on the list.
Going out to buy some snacks /nice quick to prepare food that will keep you going is your first task!
I use music to get myself pumped and provide entertainment whilst doing chores. My favourite is "make a man out of you" from Mulan. It is much easier to feel energised to do a chore when loudly singing "LET'S GET DOWN TO BUSINESS, TO DEFEAT THE HUNS!" Picturing Mulan retrieving that arrow from the pole is truly inspirational.
I find "just squeezing something in" a good strategy for getting more done than you thought you would. Eg, "I'll just squeeze in washing 2 dishes before I have a shower". Sometimes you will only wash 2 dishes that's fine. Sometimes simply starting the task is enough to prompt spontaneously blasting through all of the dishes - a win! For some reason I am paradoxically motivated when I really need to be somewhere else(!). I use this to try and get stuff done on days "on" as well as days "off".
Plan the most activity for when you are most energised (eg are you a morning or an evening person) even if that means staying up until a weird hour. Plough on once you are "on task".
Put your phone / laptop out of sight and out of reach. Do not engage with the Internet during chore time. If you have removed this distraction but still don't feel motivated to do chores - do something energetic instead (eg dance around house to "I'll make a man out of you" from Mulan) because something fun but energetic will give you energy and motivation to complete chores.
Hope that helps! I do not always practice what I preach. Sometimes despite your best intentions you will spend 4 days off lazing about and feel crap at the end. Everyone does this sometimes. Don't feel guilty just make a plan. Squeeze stuff in. Like someone said if you life is really busy and you have the cash consider a cleaner!