I took the "it's an addiction" mentality to kick my sugar habit and I think that's why it worked so well for me.
Any time I thought about eating something I shouldn't, I literally reminded myself that it's not food. It's a drug. I know it's a stretch and a bit insulting to those that have battled drug addiction but I needed to approach it that way so that I could beat it.

I also had inspiration in others struggles. My daughter was a fairly recently diagnosed T1D and everything seemed like it was harder for her. My niece is a recovered drug addict that had been released from prison not long before I started keto and she came home so empowered and happy with her recovery and ready to begin a new life. My dad was battling cancer and had a hard time even eating a minimal amount of food every day because everything tasted so bad from the chemo. But he gulped down at least one meal a day to try to stay strong.
By comparison, my struggle simply not eating crap food seemed embarrassingly easy. And I got mad at myself for being so weak! And I used that anger to kick my own *kitten* into shape!
If they could do what they needed to in order to become healthy, then I could most certainly eat an egg or bacon instead of candy!!!
And you can too!

Also, there are a few threads here that might help getting your son involved and his buy in to the process. You don't say how old he is, but getting him involved in the process of selecting and preparing meals makes him more invested in and willing to try some things, just in general. While it will take time, no matter the age, it can happen, especially if it presented more as an adventure and not as punishment.

Let him pick a new food or new recipe to try once a week. You can present him with 2-3 acceptable (to you) recipes, if there are too many options. Look into healthier versions of his favorite foods. Keto pizza was readily embraced at my house. Maria Emmerich (mariamindbodyhealth.com) has some great conversions. Even for special occasion foods like S'Mores in keto version (yes, a graham cracker, a marshmallow, and a chocolate bar, all homemade...and keto friendly for the occasional camping trip, etc.). Things like that are not for every day, and so are worth some effort.

Personally, I've learned to love zucchini noodles and spaghetti squash. Pretty much any "first" veggie can be spiralized, etc. There are swaps for Tater Tots (made with radish - it cooks out the "bite" or cauliflower or even things like jicama, etc.)

Also, acknowledge to yourself that the food industry intentionally makes foods as addictive as possible since they want you to purchase more of them and eat more, etc., they add chemicals or sugar/salt to make them taste better, and the balance of fat and carbs and sugar and salt literally makes the foods addictive little mouth bombs. While, as was indicated above, that this is not to be compared to actual drug withdrawals, the chemicals involved are similar, just to a lesser degree - it is still overwhelming and all-encompassing when you're in the moment. The difference being, for me, is that I could quit a drug and never be exposed again, theoretically. But we have to face down our food demons all the time... Sugar withdrawal is a real thing. Serotonin will drop with the dropped consumption. If your body has difficulties converting and using it, mood will drop. Amino acids might be needed temporarily...

Also, since you are a diabetic, look into insulin resistance. It creates a starvation syndrome within overeating... It's kind of hard to explain. Basically, you get hungry, you start smelling your food, you take your first bite. Body releases a rush of insulin to accept the incoming glucose. However, the body either can't find the insulin (transports the glucose into cells), the cells refuse the insulin/glucose combo, or there is simply more glucose in the bloodstream than the insulin can handle. Insulin hanging around without glucose will actually signal your body to eat more to use it it. But if your body can't find or use the insulin, and the glucose stays in the blood stream, your body will keep making insulin and you will keep getting hungrier. And then the scary part starts. The body says, Oh, look at all that insulin. There is more food coming, so let's get all this glucose out of the way and go store it as body fat... But you've eaten all your calories. But your body screams at you that its starving...and yet your body got NONE of the nutrients out of the stored calories, you got literally fatter with fat storage...yet you still feel like you are starving and your body is undernourished.

THIS ^^^ is why it feels impossible to break the carb cycle specifically, and yet why it is the most important thing you can do for yourself...

I have to write out the worse case scenario or create the stories in my head, etc., to get through sometimes...

You've gotten a lot of great advice here...good luck. Once you finally break through a bit, it'll be scary, how much you can see all these things in action...but it will be oddly refreshing to feel "in charge" of you again, instead of your body forcing you to do things that make no sense to you rationally...