It's not OCD. I looked into that in the past regarding thoughts I barely have now. I don't think OCD obsessions change rapidly or circumstantially.

It's most likely a kind of rumination.

EDIT: I just looked over that checklist. The majority do not apply to me at all, the few that do are either 1) very minor and occasional or 2) true in a painful sense, but only onset in the last 3-6 months (most notably a quasi-religious concern with right and wrong, and a frequent need to tell and confess). Also, there's nothing about obsessive thoughts or plans of punishment, or would that go under scrupulosity?