Light Headed When Laying Down. Diarrhea, Heartburn, Trouble Sleeping. Related To Anxiety?

Last night while laying down, I suddenly felt light headed (like I was going to pass out), but what ran through my brain was that it was something to do with my heart (I have WPW ). I saw nor felt a change in my heart rate , and the light headedness subsided within a few minutes. I also began to feel feverish, but had no temperature. I also had mild diarhea, which is now a tad worse. I aslo had slight heartburn from just eating chili, but that went away by morning. Naturally, I felt anxious all night and had trouble sleeping. I managed to fall asleep twice, but woke up with a somewhat damp pillow. Other times when I fell asleep, I immediately woke up, as if I stopped breathing . I assume this has to do with the anxiety and nervouseness. I am a 30 year old male, and for the most part eat somewhate healthy. Can you advise me, or provide some reassurance? Thanks