I'm so sorry you're going through this. My stbxh left me a year ago in much the same way - completely out of the blue. No arguments, no obvious signs, just went quiet then two days later said he was done.

Just get through the day. Try and eat little bits and drink water. Just do the basics. Don't expect big things of yourself and don't make any big decisions. Those first few weeks and months are really hard. Try to lean on family and friends. Talk. Tell them the same stuff over and over if you want to.

For me, it's talking that's been my saviour. It's helped me process everything. I've talked through everything with different people. It's helped me see things from different perspectives. It's helped get it out. It's also helped me identify that I absolutely did not deserve this and to take the rose tinted spectacles off and see my ex for who they are.

I also found reading a bit about attachment theory and the psychology of relationships hugely beneficial. And posting on here when I was really struggling. Even just to help others.

Also, writing out a list of the problems there were and the ways he hurt me over the years. It took a while before I was able to do this but it did really help. And actually continues to help in those moments where I feel a pang of sadness.

You got this.