I didn't want to read and run on this one, as I felt in a slightly similar situation recently. Very long term relationship, two small children, I felt things were slightly "off" and when I asked he shared he felt unappreciated, worn-out, and like I was constantly negative and hard to be around. Obviously not at the same point as the conversation you had with your DH, but I felt like it was a warning sign I didn't want to ignore because it could snowball very quickly. It's very unlike my DP to share emotions so the fact he said it, meant he had been seriously thinking about it.
I think step one is deciding what you want. Do you want the relationship to work? How do you ideally want it to look like? What's your best case scenario, what would you settle for without being unhappy, and what's your LTB boundaries.
Typically in these scenarios other women will tell you to communicate more, and that's the advise I found most when I looked online. However, one of my friends gave an honest opinion that men are fundamentally different than women, with very different wants. Over-communication can leave them feeling pressurised. Whereas what they want is feeling appreciated, occasional time to themselves, good-looking wife, happy kids, full stomach and empty balls. It sounds so base when you type it out, I know.
Instead of focusing on division of labour, communicating feelings, talking about how we wanted our partnership to work, I decided to remind him why we go so well together. I organised babysitters for date nights, initiated intimacy (obviously only when I actually wanted too), focused on showing him I care in his own love language, sat us all down to eat as a family every night (ready meals a lot of the time but still), bit my tongue every time I wanted to complain about the state of the house, and started leaving the kids with him two evenings a week to go to the gym, and encouraging him to do the same. Within a few weeks we were easily back in a good place. I also felt more positive, having carved time to myself each week, and that benefited our whole family unit.
Then from there, I reframed division of labour conversations in a positive way. I led with appreciation and understanding of what he does for the family. Sometimes this was difficult, as tbh I was doing a lot more IMO. We're now in a much healthier place. Yes, it was frustrating to have to be the one to ask about the issues, and then problem solve them. It for sure felt like a lot of the mental load and in an ideal world I wouldn't have had to do that. For me though, I love my DP and truly wanted our relationship to work, so it was worth it to me to do that.
I can really empathise with your situation right now, and hope it works out for you. 💐