This used to be a really common experience for me and still is sometimes. For me it has to do with 2 things 1. Due to my childhood abuse and neglect love was inextricably linked to shame and fear for me....it took a long time to realize there might just be compassion, caring etc without anything bad waiting behind it and
2. Because of my childhood being so painful and neglectful my Ts care awoke excruciating longing in me.
I'd leave sessions and plunge in despair.
Fortunately most of that is behind me now