How do I let a good man down

I don't know how to love a man that will stick around.
I don't know how to feel right when things are safe.
I don't know how to be loved.
I don't know how to act when things are healthy.
I can't seem to live the life that I want.
There are some nice boys in my life that like me.
And I don't know how to love any of them.
One guy that has been through a lot of tough things in his life.
He makes me feel safe and he takes care of me.
But I get the overwhelming feeling that I will fuck him over.
That I will fuck everything up.
I don't know how to handle someone that is that nice.
For his sake, I can't get close to him.
And I've already started drifting away.
Another guy that says he likes me and seems honest and true in his intentions.
He has interests that are similar to mine
and his sense of humor and oddness is very much like my own.
But I am afraid of him and afraid to get close to him
because I'm still waiting for the other shoe to fall.
I'm still trying to figure out what the catch is.
Then there is a guy that I talk to alot
that is coming to see me all the way from Seattle.
And now that it's becoming real, that I will actually meet him,
I can't help but feel distant and scared of reality as it draws near.
I have wanted to be in a relationship for a long time.
I have wanted to find a nice, kind man to spend my days with.
But whenever someone gets close to me
I don't know how to act.
I don't know how to be liked.
I am the one that does the liking.
I am the one that puts myself out to be hurt.
I don't know what to do if things don't look like they will fail.
I don't know how to be in a healthy relationship.
All I've wanted for the last 6 years is to be in a healthy relationship.
Now that I have chances to do so,
I don't know how to accept them.
I can't be with someone that respects me.
I am only attracted to those that I have no chance with.
I only want those that will hurt me.
I have tried rationalizing it.
I have tried forcing it.
I don't know what to do.
I don't know what is wrong with me.