Yoctopus, I can identify with feeling the need for someone else to be happy. I attached myself to strongly in that way in two of my younger relationships. It was only after a period of time alone, that I really felt free and happy. I realized I could be happy alone. It was a very good thing. Sometimes, as a mother, and with stress, I wish I could go back to that lovely little apartment. It was so tidy, and just me and my cat, who adored me.
I think you are doing good work on yourself, going to therapy and looking for happiness within yourself.