OP, there's a really good book that helped me when I went through this. It's called "It's Called a Break-up Because It's Broken", by Greg Behrendt, the US comedian who was an adviser to the scriptwriters of Sex & the City. I found that book really helpful - partly because it made me laugh, but also because it tells "real life" stories of other people the author knows who went through awful break-ups, which is kind of what you need to hear. That others have been through worse and survived, and even thrived, in time.
Going through a break-up is horribly isolating because it seems as though everyone else is "happy" and "normal". But that isn't true!
I personally am someone who can listen to a friend going on about her break-up indefinitely (and have done, on many occasions - in some cases for years!), but I've found that a lot of people can't cope with it. Sadly, that's just reality. A friend of mine once said that she decided to go to therapy to talk about her break-up so that she "didn't piss her friends off" by talking about it all the time.
It's normal to want to talk about it - you're traumatised. I've been through this myself several times and do you know what really helped me when I had no one to talk to about it? (Because they were sick of hearing about it!) I wrote it all down in a journal. The words poured out. I wrote down everything, every thought and feeling I had - about me, about him, my hopes and fears, my longing, my emptiness, my bleakness - everything I could drag out of the farthest reaches of my being. And it really, really helped.
Because when you go through this you feel as if you're going mad. Those thoughts go round and round in your head and they torture you. You need to get those thoughts out of your head - by talking or writing about them, and trust me, it helps!
You're clearly an intelligent woman and you sound really lovely, but right now you're not seeing your ex-guy clearly, only an idealised version of the person you built him up to be.
Long hair, musician, baths, conspiracies, Sudoku, living with his mother ... yeah, I've got a picture of him vividly in my head. This guy is everywhere. We've all met someone like him. A friend of mine met a guy just like this. Long hair, musician, wild looking. Good looking, too. Physically he was exactly what she wanted. Another mutual friend of ours, however, knew about his past and it wasn't pretty. He'd left a trail of broken hearts behind him. All of his exes were "mental", he claimed.
My friend knew some of the women and they were lovely, but were left nervous wrecks. He caused chaos and heartache wherever he went. He did the same to my friend - left her after two years of living with her and married an OW literally within months. It totally destroyed her and it took her years to get over him.
I'm not saying that all long-haired musicians are a nightmare - I'm sure that many are not! - it's just that, as a PP said, a picture is building of this guy. He sounds like a total LOSER, who one day you will be SO GLAD to be shot of. He's done you a HUGE favour! And in time you'll see it. Just not yet.
Do you have any knowledge or a picture of his past? Has he told stories of "mental" or "psycho" or "schizo" exes? (They won't be - but the common denominator will be him.)
Hang in there hun. I can tell you, as a survivor myself, you WILL get through this. You're doing all the right things by maintaining no contact. Keep going. Try not to find out any info about him - don't look at his social media - anything you find out will NOT help you at this stage. Ignorance is bliss. Keep busy. And buy that book! It will cheer you up. It's 1p (used) on Amazon or you can get it on the Kindle for £4.49.
www.amazon.co.uk/Its-Called-Breakup-Because-Broken-ebook/dp/B002RI9J5A/ref=sr_1_1_twi_kin_2?s=sports&keywords=it%27s+called+a+break+up+because+it%27s+broken&tag=mumsnetforum-21&ie=UTF8&qid=1544579192&sr=8-1