If memory serves, you are a Taurus like me?
I think one of Taurus' 'mistakes' is to be overthinking and probing and focusing on serious things, inner work, too much and too often. I too have that tendency. And that in itself isn't bad, I find it's how I learn, grow and so on.
But it should be balanced with joy. You mustn't forget that we are here to live a full life experience and that means experiencing joy and happiness.
Now I don't know you apart from what I read here, but I have sometimes wondered if you are like me, and spend (too) much time on working towards getting happy by thinking as opposed to
doing things that make you happy. Like going out there and having some good old-fashioned, simple fun.
Maybe something inside you is ready to open up to new love and subconsciously triggers your TF too, because in your heart both are connected. Hence him showing up out of the blue on FB feed.
The Universe responds to what's active in your vibration, Law of Attraction.
I think lovingly let go of him, by which I don't mean forget about him, more like energetically sending the message you're all right, you love him, smile and say goodbye (for now). Not unlike a phone call with a friend to let them know you're fine, then you hang up and move on with your day.
Then focus on this new guy that makes you feel good about yourself. Enjoy it!
SOmetimes we just need to kick ourselves in our Taurus b*** to not be so serious all the time. At least that's how I feel a Taurus can be, and maybe you need such a kick up the rear end too
Live! Find some happiness, lightheartedness and fun.