Please Explain

I want to understand
Really, I do
You say you care
Even used to use the word love
But things started to change
It has to be me
Is it possible
To be impossible to love
I left myself open
I am aware of the flaw
Aware that I invited you in
Freely gave of myself
My loyalty and love
Feeling useless and Broken
Stupid for believing I was enough
Even when giving my all
And a little bit more
I went in with trepidation
But it seemed real at the time
Cast aside
Time to lock it down
Retreat and be small
It’s the only answer I have
It is all I know
I was striving to be better
Even starting to grow
Now with my heart filled with pain
I have but one request
Please explain