Blackhorse... I've been through what you're going though many many many times. I'm still learning what to do but my conclusion has been that my fantasies and desire for men in this way has nothing to do with the actual man but instead how I feel about myself. How I want to be loved and taken care of, and instead of focusing really hard on doing that myself, I seek out someone else to help me feel that way.
On the other hand, interdependence is healthy an I would research the interdependence theory. I've been really getting into it lately and it's helping me.
Some key points I've learned from this theory:
Any relationship has multiple cost-benefit analysis that we go through. I suspect for me my problem if when I do this analysis I take on way too much risk because I'm used to doing this. In my life the only way for me to get affection from my parents was to conform to them. As a survival mechanism if someone who I am close to starts to pull away I react by clinging and my feelings growing stronger for them because in my mind I'm being abandoned again.
I have a lot of PTSD and childhood trauma I am working though.
I don't know your life story, but I have to wonder: how much time and effort are you investing in yourself? What do you do for yourself that has nothing to do with other people? What situations have you been in lately when you had to let someone down because you had to take care of yourself instead? When do you put yourself first?
The more I focus on myself, my needs, my dreams, my goals, the easier it is to tune out this romance fantasising. Understand that desiring companionship is natural and hormonal. It's out of your control you literally have hormones telling you to find a mate and reproduce. But part of maturing and growing up is being able to see those urges and resist them, channel that energy into something else.
You don't need a man to love you to experience happiness, and for me, until I truly believed that I was never going to have it. I would always put my hopes and emotions on another person hoping that they would fullfil me.
For myself, this intersects with a quarter life crisis I'm going though. Im trying to form my identity, understand my purpose and drive for life. Finding a sexual partner in my opinion cannot be your life purpose and unconsciously for the majority of my life that's what it was.
Develop yourself. Look inwards. You do this for long enough even if you experience these feelings you can push them away. It's a skill and you have to develop it.