Separation anxiety

My SO and I have been together for almost 5 years and we have NEVER had to be apart for very long. I now have to go to Texas for 6 days and I feel sick to my stomach about it. The longest we've been apart is 3 days but it was never that far of a distance either. It doesn't help that I'll get back late at night on December 1 and on December 2 he has court. I'm just really scared and worried. I feel like a baby for feeling this way but I just can't help it.