How do I heal my limernce as I get older and let go

I'm 23, and I noticed that I have this attachment to people who could be no good or to people I used to love... My last breakup really hurt me, and I feel like I'll never get myself back... He gets to live his life without this betrayal, this hurt, this missing feeling, but I'm not getting any sleep. I feel empty every day and feel like I have no purpose anymore... What can I do? I feel like I don't need to be here anymore. I lost all my family and friends for this person continuing to give them money just to talk to me, and I feel like there's no purpose; I'm just being used ...