I had a SO but she left me and since I was so attached to her I have anxiety about her like is she doing okay is she alright is she happy and if she is

If she is with someone else...

That crushes me lol but well how do I let go of her
How do I let go of the anxiousness

I mean to any person looking from outside if a person hurts you then you don't even want to hear their name but I guess it isn't so for me because I still think about her and so would love some tips for all of this