I hope this posting finds you well.

I'm in need of some advice. I have a strong tendency of feeling abandoned and when I do so, I start bombarding the other person with messages and/or phone calls. For example, a few weeks ago I met with a friend whom I don't see very often as he lives in a different country. We had a nice evening. We had dinner and went to see a movie. I expected him to come home with me afterwards (because we usually sleep together, we're not a couple, but we're both single and we're like "friends with benefits"). When he said that he felt very tired and wanted to sleep at "home" (a room he has rented for his stay in this city), I felt extremely sad. But I didn't tell him about it and as I rode home alone I felt the emotions rushing through my body with an enormous intensity. I even started crying on the platform, waiting for the train. When I was home I sent about a hundred messages some of them saying that "I am so ugly, of course you don't want to be with me." Some of them saying that I "hate" him and some of them saying "Please come back." I had to get his attention somehow, I felt forced to do it even though I knew it was a bad thing.
I have experienced similar things very often in the past. Also, it bothers me a lot more than it should if, for example, a friend doesn't have time or if my therapy session ends. I feel abandoned and unloved even though I know it doesn't make sense. But the extreme behaviour (the phone calls and the messages) only happens if it is a man I had sex with.
Does anyone have similar experiences? The problem is that my feelings at that moment are so strong and horrible that I don't know how to stop it. I would need some kind of technique, something I could do to distract myself or just feel like I can be alone and be fine. How do you cope with situations like this?
Thank you and have a lovely day!