I can totally relate, except I wasn't a relationship jumper. I simply avoided them entirely. Convinced myself they weren't worth the trouble, the pain, the mess... Now, at my age... well, maybe I hung on to that mindset way too long...
Don't do that. You ARE worthy of love... start with loving yourself. Get to know YOU, your likes, dislikes... your manner of communicating, of listening. What you like to do for fun, what pushes your buttons, positively and negatively.
When you find yourself complaining about your life (I hate this... why does this always... how can this happen...) counter each negative statement with a positive one about your life... no matter how simple it may be.
Therapy is freakin' awesome for this kind of stuff... cognitive therapy helped me understand the errors of my thinking and see myself in a new light.
You are worthy.
Best to you.