I have known a woman for 20 years, and been romantically involved with her for 10 years. We have never been able to get it right, and the reason I would give it is that she engages in push/pull cycles that make it impossible to establish a good base for a mutually beneficial relationship. Still, I care a lot for this person. 

A couple of years ago she went silent for a couple of months, as she sometimes does, and I decided to take advantage of a once-in-a-lifetime opportunity in another country, where I am now. Naturally, the time before I left was some of the best time we have ever spent together. When I did finally leave, we weren't in any kind of formal relationship: while we kept in touch, she dated other people, and so did I.  We have had our ups and downs since then but its been mostly fine between us, with no major breaks. 

Earlier this spring she asked when I was coming home but was being very distant so I didn't engage too much with her. A couple of months ago, I wrote to her saying I was coming back, and wanted to give it a real try, if she was willing to do the work it would take. She told me she was seeing someone, and then a few weeks later wrote saying that she just didn't know what to do. A couple weeks later, she wrote saying she as going to focus on her relationship. 

I respect all of her choices, they've never been a problem for me and I understand why. Obviously, I believe she deserves to be happy and I want that for her, with me or with someone else. On the other hand, if she is not going to be with me, I don't want to do emotional work for her, because I can't love both of us by myself. 

About ten days ago I sent a short Whatsapp message just to say hi, which never went through. A few days later she posted a picture of a guy on Instagram, and I unfollowed her. 

The very next day she sent me a message, neither the contents of which, nor the purpose of, is entirely clear to me. She sarcastically thanked for me unfollowing her, then went into a long justification for her silence and an explanation of how she is bad with boundaries and doesn't know how to be just friends with me, and finished by suggesting that blocking is better if one wants to do more than "send a message". 

I wrote back just saying I unfollowed for me, not for her, and that she didn't have to justify her happiness to me, and of course I wouldn't push on her boundaries. 

A day later, she blocked me. 

I am hurt because now our communication has been entirely cut off. Before, there might have been distance, but there was always a way to check in and say hi. Now there isn't. I also don't understand why she blocked me; I already couldn't see her posts on her private account. Now, I am wondering what is best to do both for me, and for her. I think only I can decide what is best for me, and I am working on it, but I was hoping to get some insight into why she did what she did, just to help myself. Anyone who reads all of this, thank you.