Ammidyphobia is some sort of obsession it is the exreme fear of being left by the someone you love,it usually leads you to do things you would have normally never have done just fpr fear you might me left behind.
ammidyphobia ammidyphobia-fear of someone you truly loved leaving your side.
The technical term for fear of abandonment is "autophobia." You can learn more about autophobia via Related Links, below. It seems people believe its autophobia but it doesn't describe it enough, if you ask me. Autophobia is being left alone, but I think it relates more to Ammidyphobia which is a loved one leaving your side...
Separation anxiety? It depends on the situation, but unlike spiders (arachnophobia) or heights (acrophobia), I don't think the fear of losing someone is as simple so to be summed up in one ____phobia word. Adjustment disorder? Post Traumatic Stress Disorder? Many people with Borderline Personality Disorder also struggle with a pivotal fear of loss (and rejection). I believe in your case, the context would come in very handy. Hope that helps a bit-- I'm not a medical professional or qualified to provide any sort of definitive answer to your question. But if this is something that's really been bothering you, it might not hurt to consult someone who is. Best of luck, Alyssa