sjkero:

This way of looking at it may help. When your T is helping you and focused on your issues, her other clients may be feeling similarly to how you feel when she has to be attentive to other people. The secret is to learn to share people without constantly anticipating being left high and dry (much easier said than done, I know).

I hope you aren't feeling guilty about your emotional reactions - given past expectations they are logical in their own way. You're not crazy weird, you have fears due to abandonment as you said.