@squishy.
Looks like you've been looking at finances and secure jobs etc which is brilliant.
Your only a year older than me.
I still feel in my 20s op with an awesome dh who also feels younger.
Because we have fun together and enjoy each other's company,get each other's humour and want to spend time together.
Don't ever settle. It's not worth it.
Your a strong person and you deserve to be happy and if that means divorcing and splitting the house so be it.
If you know financially you'll manage and Youl also get a life and friends back again and freedom do it.
Get everything in order as quickly and methodically as you can and then seek advice to get the ball rolling.
I was in your shoes in my first marriage.
No kids but more lonely than if I had been single. It just felt wrong.
I had brought it all up so many times and then one day I just thought fuck this,no more and I started to get the ball rolling.
Didn't even tell ex dh what I was doing I figured I'd told him enough times it was not a happy marriage but he was a selfish fuck and didn't care enough to do anything.
When he got the divorce letter from my solicitor he was absolutely gob smacked 
He actually had a man tantrum when realisation hit that I wasn't going to be his cleaner cook and surrogate mother anymore and had had enough.
The first words that came out of his mouth were
"You can't leave me"!!!
I said I'd been trying to talk to him for months and he didn't want to acknowledge me at all or change things and is finally snapped.
We stayed in seperate rooms and didn't talk for a good couple of weeks but I was out working or out at the gym or with friends.
I ate out more to avoid buying and cooking food at home and I actually took my clothes to my parents to do
The house went on the market and every time a viewing came up I would shove all his mess under his bed or in his wardrobe,do a surface clean and leave them to it.
It sold quickly to a cash buyer which was perfect.
I secured a mortgage and bought my own small place.
He moved bak with parents and now lives in a house share so clearly hasn't managed to grow up at all and he's in his forties now.
I look back now and shudder
Do it op. Don't look back