I am very sorry you are suffering so. But you already know that the intensity of your reaction to rejection is way too much — and has gone on much too long. Since this has gone on since childhood, it suggests to me that there was a traumatic experience in your childhood from which you have never recovered. I’m guessing that maybe there is something about the way you are in relationships that contributes to people leaving you.
You already know that trying to get back with the people who asked you to leave is not a realistic option. You do need therapy for this.
It’s hard for me to believe that there are no therapists in your area who keep late afternoon, evening and Saturday hours. Most therapists in private practice do. And many offer a sliding fee scale to make it affordable.
I suggest that you talk to your primary care doctor about getting a list of names of therapists or clinics in the area who can help you. If you have a faith, you might also look into whether the clergy are available for free counseling.
Rejection is an inevitable part of life. Not everyone “clicks” in the same way. Not everyone we admire or want to befriend, returns the feelings. It is unrealistic to think you will never experience it again. What you can change is your response to it.
You have suffered with this problem for far too long. I really hope you will make a concerted effort to find the help you need. Therapy will help you gain insight into what perhaps you can change so you are less likely to be rejected as well as how to manage it when it ihappens.
I wish you well.