I broke no contact and now I feel like I got stomped on...

(the whole story of my breakup is on my other post, for anyone interested on a backstory)

So, either I became super paranoid or I'm quite sure that she has been flirting online with a couple of people after we broke up (im 37M and she is 32F)... In the meantime I can't even think of another woman... Even though I knew it was the wrong move, I decided to text her "Hi! I was thinking about you today and wanted to see how you're doing! You good?"

Needless to say, I got left on "seen"... We had a very civil breakup and we are still connected on instagram (she higher stories from me - not my friends though - and she still watches my stories).

Part of me is starting to hate her for her cruelty and another part of me is agonising for her to come back... How can a person you dedicated 1.5years of your life to them not have the human decency to reply to a simple message?