I had a very different experience than you so take this for what it is worth. My husband did very little gaslighting (or even direct lies) because we were having to live apart for a LONG period that more than encompassed his affair. His lies were of omission - it never occurred of me to ask - and he certainly wasn't offering.
And yet, for a solid 12-18 months I constantly questioned my own judgement - and whether I could trust that anything good was real. So I think part of it is just trauma and the body and minds way of dealing with it. Brene Brown's description of "Foreboding Joy" really rang true for me. However, with time and a concerted effort to build new neural pathways by reminding myself regularly of how often I HAD made good judgement calls and life HAD been good, I have found almost all of this leave my system in year three post DD. The feeling occasionally still comes to visit, but it is rare and passes quickly when i put it through a "reality test". So glad that you are feeling so much stronger!
BS - Female
Married 27 years, one adult child DD May 2016 “When we are no longer able to change a situation, we are challenged to change ourselves.” - V Frankl