I think it's better to go in and talk about it, though I understand your reluctance to do that with this T. I just don't think ghosting would have the effect you wanted it to have. Plus then I imagine you'd have to pay for the session? Now if you just want to take, say, a week off to think about things and cancel the session in advance rather than just skipping it, that's a bit different. But I think it's better to go in and say "I thought about skipping this session because I'm feeling _________."