Past traumas coming back to haunt me

Sorry, this is a little long. I recently had a memory pop back into my head and I can't get it out again. To explain, I need to tell a couple of stories:

Story 1:
When I was a toddler, I was in a day care center. They were potty training me and my classmates. Rather than positive reinforcement, they used shaming and punishment. Having an accident meant getting yelled at, paraded around in front of classmates in only a diaper and sitting in time out. One of the policies of this wonderful place is that you could not go on field trips unless you were completely potty trained. I remember they use to take me to the front of the building to watch all of my classmates get in the van to go on their field trip. I still remember the door to the van sliding closed and the van driving off and leaving me behind.

Story 2:
When I was a teenager, I was on a mission trip in Mexico. On the last day, I got distracted taking pictures and the van I was supposed to ride back to the hotel in left without me. Keep in mind, there were only 8 of us in this van and we had been riding in it all week. We all got to know each other, and it should be obvious if someone is missing. Also, it’s not like we set a time to meet. They just climbed into van and took off without telling me. This van also had one of those sliding doors like the one from my day care. I barely managed to get in another van before everyone left and I got left behind altogether. I remember crying in the shower back at the hotel and feeling depressed days afterward. I never found out why they left me, I was too shy to ask.

I seemed to get over the incident in Mexico, and I hadn’t really thought about in years. Then a couple of months ago, the memory came back, and I’ve been obsessing over it. I keep replaying it over and over in my mind and my mind’s version keeps expanding on the original, coming up with fictional versions:
• They did leave me behind and I got heat stroke.
• I tried getting in another van, but they refused to take me.
• I got robbed walking back to the hotel. And so on…

It’s as if my brain is scrutinizing all possible outcomes. So why is this happening after so many years? I understand me being triggered by the event because of the similarity of what happened when I was little. But why now? The only thing I can think of is that a couple of months ago, I started using a CPAP and I've been sleeping more deeply. I know correlation does not always equal causation but ever since my sleep pattern changed, my anxiety and depression have been come unpredictable.

Also, is there anyway to get a clearer picture of story number 1, like through hypnosis? All I have are vague memories that I have to put together like a puzzle with missing pieces. Any insight would be helpful. Thanks.