Saw STBXH in Public

I didn't want us to end. I wanted to fight for us and find our way back to each other. He obviously felt differently. A month ago he told me he wanted a divorce and everything has happened really fast. Almost two weeks ago he moved out and I haven't seen him since. He sent me a message earlier this week asking me to send him the money for the internet bill. I sent it and went to check that it went into the account we used for bills, etc when we shared our life together and I saw he paid for Tinder. To say that stung is an understatement. I get that he's free to do what he wants now but it still hurts to think he's moving on so fast after being together for 13 years. Today I was out with my (used to be our) dog and some friends. He walked past us and it was like me and my dog didn't exist. Like we were complete strangers. I'm barely hanging on by a thread at this point and I feel so broken. I am in therapy working on letting go and rebuilding my self worth but if I'm being honest, all I want is my husband back. I want my best friend and partner back. I don't want to let go and I feel like I'm nothing. Have any of you run into your STBX in public and just acted like strangers? All I wanted to do was yell out his name and go hug him. The feeling of seeing him and being a stranger made my heart drop. We don't have kids but he did mention he still wanted to see our dog but now I'm thinking I'll never hear from him again. How can someone that once loved you just drop you and act like a stranger? That's it, just had to vent. Thanks for being such a supportive community and it's nice to know I'm not alone.