First I think you are being very hard on yourself op. Three is a difficult dynamic, especially if you are all strong personalities. And as you say, it is quite intense for your son having two sets of fog lamps on his every move too 😄.
It's not your sole responsibility either. If your DH is tricky, your ds is probably copying him as DC often copy the same sex parent. .Your husband needs to step up in this situation too. In what way is he "tricky"?
Thirdly, your ds may not have physically gone through puberty, but he is growing up and his behaviour is telling you something; so listen to it. It's normal for tweens and teens to start splitting themselves off from parents in order to become individual independent adults. So his behaviour could be telling you that he is ready for more autonomy and responsibility and he is telling you to step back a bit and let him monitor himself a bit more.
You may need to re-think your parenting style. Perhaps sit down with him and negotiate the rules. Ask him what he thinks is reasonable in relation to sugar, study, sleep, exercise, gaming, friends etc, so he signs up to the programme. So as a pp said, the rules are the rules and there's an agreed consequence if they are broken.
At this point you slowly switch from being a parent who enforces from the top down to one who runs alongside your child, encouraging, and asking them with genuine interest, I wonder if you are you going to be successful in your project to self monitor this week? Are you you going to be successful in your struggle to develop SELF discipline?
This hands the responsibility over to him. So when he asks something like "can I go and see my friends tonight?" when you know he has homework, instead of saying "no you can't" you say something like , "mmm let's see, I really hope so and I'll be interested to see if you can manage both and get your hwk done properly".
Stepping back is one of the hardest things when you have been hands-on for 12 years but it's so important with adolescents or near adolescents to let them suffer the consequences of their decisions and the earlier you do this the better.
If he doesn't do hwk to a good standard he doesn't get to game.
If he doesn't get up on time, he's late and he gets a bollocking from school (obviously as he is younger, you have to gradually hand over responsibility for this one)
He gets a reasonable amount of snacks put in a tupperware box for the week and if he eats them all at once then, tough, you are not buying extra.
Is it such a disaster if he wants to do things in his own way as long as the end result is the same? Why should he do everything the same way as you? He's an individual with his own preferences so allow him some freedom to exercise them?
How much are you doing for him? Are you cooking for him, cleaning his room, telling him when to go to bed, going in to wake him up, telling him when to shower, laying out or directing him to clean clothes? Do you drive him everywhere? Is his main role in life to comply?
If so, then you need to step back and shake things up a bit. He's twelve. He is capable of taking over responsibility for a lot of these things. Step back and observe. Let the battle be with himself, not you. (Obviously with some things like food there has to be a gradual hand over but my DC cooked a meal once a week from the age of twelve.) Does he do chores? Peel potatoes? Empty bins? Hoover his room? Change his bed? Walk the dog? Does he go food shopping? Can he wash a load of towels? Get him involved and contributing then it's "us all together" instead of 'parents v child'.
And to keep things interesting , start asking him for help to do things slightly out of his comfort zone. Run an errand for you by himself in town. Go to the supermarket by himself and find something obscure. Go and help someone elderly in your street.
Sign him up for the Duke of Edinburgh Awards. Get a paper round. That will dilute some of his feistiness.
A couple of other things:
- focus on that split second between him pressing your buttons, and you reacting. Literally count to ten in your head, or wear a snap band on your wrist, pretend you are being filmed, do some square breathing, step out of the room briefly ... anything ...that interrupts your automatic response and keep practicing...it will then start coming automatically...breathe and breathe again.
- use humour to dissipate tension
- never let the rules or the arguments over rules get in the way of your primary relationship because, when he is eighteen, and he is out of the house and you no longer have the same degree of control over him, it is the relationship that will stop him from wanting to disappoint you and will put a natural check on things.
Finally, get some help with this from a licensed psychotherapist, someone who specializes in families, adolescence or parenting. The fact that you feel like walking out indicates it's got to the point where you need support with this.
Are you doing enough for yourself too? Are you happy in yourself? Now he is twelve you can maybe start a hobby? Do something fun just for yourself?
Sorry for the very long essay but I can identify with so much of what you are saying. I come from a shouty family too and it's really difficult to learn how to step back, so I very much identify! Good luck!