I desperstely need a diagnosis and a treatment. This is no way to live for me.

I (M18) am an otherwise functioning individual - a high school student, I score relatively high grades, am likely going to a good university, I plan everything, I am capable of consistent work. There is stability to my life.

The only part that is absolutely messed up about my life is relstionships. I find people I cling to, imagine myself being with, and fall head over heels in love with women, without any relationship happening. I have no control over these emotions. My needs for emotional and physical closeness are exorbitant, and seem unmatched by anyone I've ever known. This also means my life is constant disappointment, and a very painful one. It's been happening for a good 5 years now, and the feeling is not going anywhere.

Please, if anyone has any, even weird idea about what might be an issue in my life, can you suggest any mental illness/ disorder this might be? I really need to read about this, and feel understood, maybe for the first time in my life.