It sounds like abandonment issues and your just putting up your wall, and since you tend to be introverted these two feelings kicked in at the moment.
I understand the Introvert, I am just as happy as can be entertaining myself, but your hubby is right you do need to give people a chance.
Abandoned
- Unbounded enthusiasm; exuberance
- A complete surrender of inhibitions
- Deserted, forsaken
- To give up by leaving or ceasing to operate or inhabit, especially as a result of danger or other impending threat
Your sister is shunning you, she has abandoned you, I think it is a natural reaction for you to automatically put a wall up and if you agree with this then your level of awareness has just increased and your now equipped with "WHY" you do this.
If you take yourself out of the equation, think of how the guy and girl felt about you shunning them for drinks.
All the best!