Love yourself (again): Absolutely! Just because someone you love doesn’t love you back doesn’t mean you aren’t lovable AND, you MUST love yourself first no matter what, if you are EVER to find someone to love you back.
There’s other stuff you love that you probably stopped doing to fit into the other’s world; find those things again because they are deeply part of who you are and how you define yourself. Self-definition: huge in this context! You have spent a significant amount of time with the other and who you are has merged into their world. You must re-organize and collect the aspects of who you are. You know these parts; grab them, pull them to you, and reintegrate them with your self to reconstruct the person YOU are!