Hello,
I can understand the feeling, I am starting training (again) and I do get some anxiety, and I cannot understand why.
I was learning to fly many years ago and I was fine, now I am trying to get back to flying, in the past I have booked some lessons but end up cancelling at last minute. I do not recall having any bad experiences when flying to justify this. Maybe because all my previous flying was done in smooth air, now my brain is wondering when I will get a bad day in the office, hence the anxienty... That is the only explanation I can think of, for me.