I can completely relate because I've been there done that--a lot. I don't think I stopped actively doing that for 18-24 months after the final dday, and I didn't stop feeling
that way for another year at least.
After the first couple of years following dday, I would catch myself starting to work myself up again, but I'd convince myself to first look at all the evidence before me; did I have any current reason to believe my H was being anything other than my true and honest partner? Was my gut screaming or even whispering to me about the current state of things, or was I circling back into the past and reliving all those uncertainties and the ensuing pain? Was I reacting to a date, like an antiversary date or perhaps a bout of PMS hitting me, or was I actually responding to a current situation?
I'd promise myself to really look at the present, and only then would I decide if I needed to open it up for discussion with my H. If I did need to talk about it, he'd listen calmly and support me through it, and the unease would run its course quickly without any drama.
Presently I spend very little time needing to keep a grip on this "self-sabotaging" type of stuff; if I get spooked or squirrelly now, I acknowledge it, do a quick reality check with myself, and move on within a minute or two. It's not gone completely, but how I handle it is much healthier and easier.