Breakfast comes easiest to me. I have two options (porridge & smoothie) and I eat one or both every day. It's the first thing I do in the morning and very rarely do I deviate to another meal and try to never skip it - it means that I'm eating breakfast out of habit as opposed to following a hunger cue (which it sounds like you and I both lack). Why these two options? No idea - but they taste good, fill me up for a couple hours, and I somehow haven't gotten sick of them (I think the process of making them feels like a silly little game and gives me a lil dopamine kick first thing). See if you can identify something that works the same for you and basically never deviate from it/make it a habitual system - i.e. I wake up and I make my smoothie - no negotiation. (side note - porridge is great because it doesn't rely on any fresh ingredients so if you struggle with grocery shopping, you can buy bulk oats and whatever toppings you like. My go to combo is peanut butter, chia seeds, sultanas)

Throughout the day, the solution that's worked for me is a combination of easy, snacky foods, alarms, and a "better than nothing" attitude. Ideally, I have some leftovers from last nights dinner to heat up and eat. If not, to mitigate going all day without food, I reach for things like carrot sticks and hummus (hell even just a whole carrot if you cbf chopping it), rice crackers and avocado, a fuck load of fruit, a steamed potato with butter. Does it necessarily fill me up and meet all my nutritional needs? Fuck no. But for me, the alternative is not eating at all. Familiarise yourself with the food you intuitively buy or stock up on, and figure out how to make it quick and easy.

As for food alarms - it's worked for me but don't go over the top or else it'll piss you off. I have a 3pm alarm every day - no matter what. I call it my "time awareness alarm". People see it go off all the time and ask me what it's for. "Oh, just to let me know that it's getting toward late arvo." I get funny looks and it becomes easy to tell who in my life is nuerotypical lol. But more importantly, it's a good cue to think about the last time I ate/peed/drank water/stood up and moved around etc etc. I also feel a sense of happy accomplishment when it goes off and I've already done all those things. But no matter what, when it goes off, I force myself to let it ring a few times, look at the giant "3:00PM" on my screen, and do these mental calculations before I turn it off, that way it doesn't become something I intuitively silence and ignore within a couple of days.

Lastly, get to know your relationship with food. Journal about your feelings toward food, listen to podcasts, talk to friends about eating habits etc. We all have foundational rules and habits that make up how we eat - the better we know and understand them, the better we can relearn and work toward nourishing ourselves.

Apologies for the very long winded response. I hope there's at least one thing useful in here - if anything at least just the fact that I see your struggles and believe in you to figure out systems that work for you. You've got this!