Missing Message Threads in OpenAI ChatGPT

I’ve already searched other forums. I cannot figure out why all of my messages that I have had on the left side of my ChatGPT-4 have gone missing and when I add a new message it doesn’t show up to the left as a new past message. How do I get them back or start them over again? I don’t know if I made a change that made them disappear or if there was a system change the now doesn’t show them as I ask them. Please help.