I was a director but it seems I have relinquished my shares 🙄
I am no expert but surely this is financial fraud? Try to find out when it happened and take that info with you to the solicitor. You may need a forensic accountant to follow exactly what you're entitled to, but generally it would be 50% of the house, his pension, and any owned businesses such as whatever he currently runs, any rental properties, etc.
If he has deliberately and fraudulently sold your shares, (or signed them over to himself) it doesn't really matter because he will still need to buy you out of 50% - that's my understanding. However if he has done this very recently then that underlines that this has all happened very quickly and as a couple of PPs mentioned, it may point to the business failing and him wanting to run away from his responsibilities.
I'm so sorry this has happened OP. I've been in a similar position myself. Proposed to at Xmas in front of his entire family, lovely Valentines day, middle week of March he decides he's not happy and wants to move back to his home town, which he knew I wasn't prepared to do. Of course he had another woman lined up, and she deserves no blame at all - I sneakily read some of their messages and she was very clear with him that nothing would happen until he had ended things with me and moved out.
It's the sudden u-turn that leaves you bamboozled. If we'd been having conversations about "I'm not happy about this, what can we do to fix it" then I'd understand. But no, we'd been happily wedding planning!
Please take care of yourself at this time, you probably don't feel like eating so try soups (Aldi actually have some great tinned soups right now, I love their Thai Green Chicken), fruit juice/smoothies (not too much as high in sugar) and if all else fails, whole milk.
Regarding your sleep, I totally empathise. I have had some success with Aldi's own brand "Herbal sleep tablets" (exact same formulation as Herbal Nytol) plus some Valerian tea and Headspace or Calm meditations before sleep.
If your GC are staying with you right now, could you have bedtime cuddles with them in your bed? I've found just natural human contact makes it easier for me to sleep. I work away usually 5 days a week but the day I get home from my soulless hotel and can have 2 days hugging my son goodnight and cuddling our animals is so much nicer.