What Causes Random Anxiety Attacks?

HELLO DR. RYNNE, I RECENTLY STARTED A JOB WORKING 3RD SHIFT TO PAY FOR MY COLLEGE TUITION. HOWEVER, I NOTICED ONCE 3 MONTHS IN, I WOULD HAVE CONSISTENT ANXIETY ATTACKS FOR VARIOUS REASONS. IT ESPECIALLY FLAIRS UP WHEN I WOULD TAKE GIRLS OUT ON DATES, HANG OUT WITH FRIENDS, OR WHEN SOMEONE RELIED ON ME TO DO SOMETHING FOR THEM THAT DAY. SURE THESE THINGS CAN BRING NERVOUSNESS TO THE TABLE, BUT IVE NEVER HAD A PROBLEM WITH THEM UNTIL NOW..... SO I WAS WONDERING IF YOU WOULD KNOW THE MAIN REASON WHY I HAVE ANXIETY ATTACKS RANDOMLY. IS IT BECAUSE OF 3RD SHIFT, OR A LACK OF SLEEP??? ANY SUGGESTIONS?? SEROTONIN???