i second what yellow frog said. if you tell them just what you said to us, that you feel "off" but can't pinpoint it, they can usually ask questions to get a better picture.
When I first started therapy up again after a brief break, I went in telling the clinician that I felt like something was happening/off, but I did not know what it was. She was pretty good about working with me to figure it out.
good luck.