I'm so sorry you were frightened like this, Boodles. It is a terrible feeling. I hope you were able to sleep okay once you were finally settled.
An OT story:
My hubby travels a lot and I go through similar "freaked out" phases. I actually had one when he was traveling last week. I was retrieving the trash/recycle cans and taking the dog out. I always move my neighbor's cans up to her garage, which meant my open garage left my sightline for a couple minutes. Per the normal set up, the garage provides access into the house. When I returned to my garage, I had an uneasy feeling. I became frightened, but told myself I was being silly and went inside with the dog. I grabbed some mace and did the crazy closet and bed check. It was still daylight, so I felt some degree of calm. However, I knew if I didn't check then, I would work myself into a frenzy by the time darkness fell.
Now, this could easily be dismissed as paranoia on my part, or just an irrational fear from being alone. However this exact scenario happened to my neighbor a couple years ago. It was 11:09 PM and hubby and I were watching TV. We heard a blood curddling scream--a sound I can assure you I will never forget--coming from the home in back of ours. Hubby (who never puts on jammies til one nanosecond before his head hits the pillow "just in case") jumped up and was out the back door in half a second. Our neighbor, a single woman in her 40s, was rattled but unharmed. Another neighbor called 911, and the neighborhood was soon awash with red and blue flashing lights.
As it turned out, the perp had entered her home while she had been walking her dog many hours earlier. She left the garage door up and unattended for a few minutes. He slipped in, went up to her bedroom, crouched between the bed and the far wall, and waited for her to retire for the evening. She ate dinner, watched TV, and was none the wiser that she was not alone for many hours. Worse yet? The dog never alerted that someone was in the home. Far worse? It was one of our neighbors and he lives a few houses away...