I used to be the same way. I was told its to do with a fear of my mom leaving me. Its hard to describe but I got so bad as I couldn't see my mom until I was sure I was home for the day or I'd freak out! When in school didn't matter how old I was if she ever had to come to school and I saw her shed have to take me home with her and spend the day with me. And I'd do the same thing and be very concerned something would happen to her in her sleep or while I slept or was away. The drs had me step back from her in a since. Every time I wanted to call her or check on her I waited 10mins to see if the feeling went away then slowly move to a longer wait time. Very hard for me to do. But it worked!! I unfortunately had to move and now live 500 miles from my mom and still no worring I think that's the best advice a dr ever gave me. Try it sometime