I feel the same way! I think for me, when I'm not seeing a T, I tend to take less risks, and just kind of go about my life as best I can, so things sail along more smoothly. Also, I tend to build these big walls around myself that keep me safe, and so I'm able to be a lot stronger.
When I am in therapy, however, those walls get broken down every session (and in between sessions as I try to figure stuff out) so I'm more emotionally fragile. Also, I tend to start actively working on my problems when I'm therapy, as opposed to just going with the flow and pushing everything aside.
So, yes, things often get pretty rocky for me while I'm in therapy. However, it is always a good thing in the long term