You may think it is strange but I have come to appreciate that pain, like my chest is going to collapse, life always moves on, and if I feel like that when something is lost that pain is inevitable if it was a good thing. To appreciate the memory I am happy to take the pain, and the sobbing.
I don't think it is unusual to only find happiness with others, we are social creatures.
But your right it needs to be done in the right way. So be careful of the internet, question if it is healthy and whether you are ready, it can be a slippery slope.
I wrote that before your last message, damn that internet, catches you out every time.
I hope you sent some consolatory texts too, anger is only useful to help you question your own assumptions not not useful in relationships.
Self esteem can be a downward spiral, but I'll try to think about that.
Back to work tomorrow so I wish you well with that, take some breaks away from your desk, go offsite for a coffee, make eye contact with everyone, say hello, time to start noticing how your demeanour can open up other people, your not stuck in a shell.