Anxiety
A feeling of worry, nervousness, or unease, typically about an imminent event or something with an uncertain outcome; can develop into a psychological condition that is expressed in compulsive behaviors and can lead to panic attacks and social issues.
~synonyms: worry, concern, apprehension, apprehensiveness, uneasiness, unease, fearfulness, fear, disquiet, disquietude, inquietude, perturbation, agitation, angst, misgiving, nervousness, nerves, tension, tenseness, heebie-jeebies, butterflies (in one's stomach), jitteriness, the jitters, twitchiness.
Learning to cope with your anxiety can significantly improve your success in relationships, work and in life.