In my experience, the only way to actually let go of a feeling that haunts you is by talking about it. Sooo, what's the big trigger? Does it follow you no matter wherever you go and whatever you do? What brought these distressful emotions up within you a week or so ago? Did something remind you of your middle childhood? What was it? Did you go through some traumatic experiences in that part of your life (thing/s that you've been avoiding for X amount of years)?

I'd advise you to look at yourself more intellectually if you can, to try and answer these Q's. Hopefully, that will provide you with the insight you're seeking, as well as the beginning of working through these emotions in a healthy manner.

Gentle hugs to you & best wishes!