Many years ago I fell in love with a girl who couldn't return my love. How would I get over her?

It’s been over 10 years and I am still thinking about her. Still romantically in love with her but know she’ll never love me back. I’ve been in multiple relationships, had many sex partners, successful and fulfilled in my career, did lots of travelling. Nothing seems to work. I just can’t seem to stop thinking about her. What can I do to heal?