Sorry, DS purloined my laptop. I had three m/c before having DS, so I do understand the feeling of not being in a good place, sorelip.
Generally speaking, Maybe one way to look at issues with food is to try to pinpoint the issue (so for example, eating as a response to stress; not having LC food at a catered lunch; whatever), rather than the result (not sticking to plan). That way, people can help with suggestions and advice.
Anyway, I also wanted to say to hangon, that I agreed with Biwi about your DH. What you want mainly is him to respect your food choices, but you cannot make him adopt them. You can buy healthier alternatives, if you are doing the household shopping. It took me three months to get XH to understand that when I said no sugar for DS, this did not just mean no sweets or actual sugar, but checking EVERYTHING. He sees the improvement in DS behaviour and sleeping but still is surprised at how much sugar is in things you don't expect.
With DD, who is older, I have just been going things like buying oatcakes instead of biscuits, offering fruit instead of desserts with sugar, buying the low sugar Cheerios etc, whilst saying less sugar is better. She gets the argument that if she eats chocolate, she expects sugar; if she eats cereal marketed as healthy, she shouldn't. Also, no white baked goods, pasta or rice- then you are also cutting down insulin spikes. These kind of changes should be manageable in your household shop and will make a difference to sugar intake.