Fallen out of love with Husband of 23 years

[BabyHare]

I have been very unhappy for the last 8/9 years. Married for 23 years, together for 25. My DD is 28 from a previous relationship and we have a DS aged 15. He was an IVF baby due to DH not having any active sperm.
He drinks a lot and has REGULARLY not come home or come home drunk. Doesn't answer his phone and has left me lying in bed with palpitations and anxiety for hours.

We have a nice house and a relatively nice 'life' but I have been living a lie for years. I do not love him anymore. He has ground me down. I think he is a total narcissist and had used emotional abuse for years.
He does not have any family at all whereas I still have my parents and quite a large extended and close family.

He WILL not accept that it is over and cries/drinks/cries. Sends awful text messages. Does not come home from London (where he has an office) until the next evening without a text or explanation as to where he has stayed.
I have been honest, truthful and open about how I feel. I am not playing mind games, I am not trying to score points or get anyone to take sides. I have not met anyone else nor do I want to.

I have been to counselling due to my mental health issues ( I am on HRT now and have been on Sertraline for 5 years, I think the pretending caused a lot of my issues). We have been to counselling but it was the All About Him Show and woe is me, pity party etc.

I need some help as to how to separate properly without him crying/shouting/telling me it is my fault and he has invested all his life to me etc. etc.

You MUST stop caring if he "accepts" that your marriage is over. It IS over. Stop responding to ANY of his abusive texts or rants. Get yourself to a solicitor immediately and figure out your exit plan. It's time to stop being anxious and start empowering yourself. You've given him enough precious time, so don't waste another day.

Do you work?
Do you earn decent money?
Could you afford the current mortgage on your own?
Your best bet is to see a solicitor and see where you would stand.
But you need to ignore his 'woe is me' manipulation.
Show him it has no effect on you.
Keep telling him you want to separate as you don't love him.
Repeat repeat repeat.
Once you have more info from a solicitor you can take it from there.
It's not doing your mental health any good to remain in this relationship.
You've now realised this.
He won't change.
He's proving that over and over again.

Thank you so much both. I am going to find a good family Solicitor and go from there. I am very scared though of what he will do as he is very up and down. When he is up, he is almost hyper and when he is down, he is VERY down. I am not reacting to his stupid rants - much to his surprise. In fact, I have not shed a single tear since December when we had a final massive row and he left for a day. The relief was IMMENSE! :)
I don't work because we agreed that I would be at home with our DS but now he is 15, I am actively looking for a job. I have NO savings, no money at all - I rely soley on him. :(

Do you have joint bank accounts? If you do, I highly suggest you take out some money and open up your own private account.