Help I think I'm ruining my kids and my marriage

I am recently diagnosed AuDHD w/ triplet 3.5 year olds. One of them is diagnosed Autistic (sensory seeking, over familiar/HELLA friendly variety).

Since starting to suspect my own autism, I recognized the way sound chaos has been contributing to my disregulation so I've been wearing headphones and taking breaks but I'm finding I still have a really short fuse or need to disassociate around my kids to survive.

I'm SO STRUGGLING to establish a warm and firm relationship w/ my kids. They DO NOTTTT listen to me because I am really struggling with boundary setting. It's like my brain can't to the naunce or understand when and how to set a boundary. I'm all SUPER boundary over the top or none at all. I feel like I don't know my own kids or how to understand them or their needs. My partner (NT and stay at home parent) just seems to intuitively "get them" and then can make parenting decisions that support them but I somehow make the wrong choice every time and it makes things work. They are all regulated all day and then I come home and shit hits the fan before I have even done anything.

If feels so shitty and out of control and is putting a huge strain on all of our relationships but it just feels like they DONT respond to me and I don't know how to fix it....I'm starting to wonder if other aspects of my autism are coming into play that are creating barriers to connecting intimately w/ my kids. I'm such a high masker and just starting to realize the ways I might actually not be as socially astute (in NT standards) as I always thought I had figured out how to be. Like I KNOW the rules for other contexts (work, friendships, etc) but I don't understand the "rules" for being a parent and I just feel so lost and shitty about myself.

Just looking for folks thoughts (maybe other parents who notice their autistic traits creating barriers for connection w/ their kids) or other reasons why the boundary setting is so hard for my AuDHD brain. I feel fucking lost.