Stop swimming across oceans for people who won't jump a puddle for you.
There is a song from the 60's that seems to pop into my head every so often, as a reminder or a warning. The song is THE SNAKE, by Al Wilson
It's a story of a women that finds a 'poor half frozen snake' and takes it home and nurses it back to health. She is quite taken with the snake and treats him with tender loving care. After some time, when the snake has largely recovered; she is sitting with the snake, stroking him, kissing him and holding him tight. And it is at this time that rather than thank the women for all she has done, the snake chooses to bite her. This is the last verse of the song
"I saved you," cried that women
"And you've bit me even, why?
You know your bite is poisonous and now I'm going to die"
"Oh shut up, silly women," said that reptile with a grin
"You knew damn well I was a snake before you took me in."
There it is... this is the defining moment. Who is delusional in this scenario? We often pin all our hopes and dreams on people that are unable to be what we want them to be. All people are who they are, we cannot make them into something else. Your choices are to accept them as they are or detach from them. That is it.
You need to take a look at what is missing in you, if you want someone so bad that you are ignoring who they are. Once a snake, always a snake. The basic person doesn't change. Each individual is responsible for their own changes, if and when they wish to undertake that challenge. You cannot change anyone.
And, never chase after someone, if they love you, they will walk with you.