Some would accuse your sign of being a little too staid for its own good. But they don't understand that a bit of caution is a smart survival tactic!
Exhibit A is your fear and dislike of surprises. It's not that you don't appreciate the effort when someone goes out of their way to surprise you. The anxiety just gets to you - now, how to learn to roll with the surprise punches...
Trying to stretch yourself a little may ensure that relationship endure. After all, your partner's style may differ from your own. This means trying new things - especially those that raise your heart rate.
On the flip side, when solo (or together in silence), calming down with a little deep breathing or yoga can get you through the anxious moments until the worst of it is over.