ACT is sort of a new wave CBT in some ways TeaCup.. I would say that it helps by adding mindfulness and values to the treatment... so instead of looking at the fear as irrational and just going through those arguments, you accept that your fear is your fear and to some extent it really doesn't matter if anyone else deems it to be "rational" or not. It is a product of your unique learning history: it has specific meaning to you.
ACT believes that we can get trapped by the language we use.. we take our thoughts literally (and this is all people, not just people with a "condition" like OCD). We think that because we have thought something that thought somehow corresponds to something we need to act upon in the real world.
Unlike CBT, ACT isn't about saying that this is wrong/irrational/needs to be disproven in order to change your experiences. ACT basically says: you feel this way, these feelings are here, but if you "defuse" from them by using techniques to ground yourself in the present and see them as just thoughts, you may still feel these things but you will be more free to live a valued life. So there is a lot of emphasis on what you want your life to be about, and whether what you are doing is "workable" for you in any given moment. It's about playing the long game rather than just giving in to that behavioural urge in the moment.
The thing is, ACT doesn't promise you won't feel those feelings ever again. In fact, ACT would say you probably will as they're part of how you respond to certain things.. it's just a matter of whether you're going to be able to continue towards the life you want while feeling those feelings or whether you'll get caught in the cycle.
So for example, you might distil your core fear down into a word like, oh, death or disgusting or whatever it is that you are desperately trying to deal with. Then you would try to see that these are just words by:
- repeating them over and over really fast for 20-45 seconds
- singing it
- saying it in lots of crazy voices, like Yoda or Bart Simpson etc.
There are literally hundreds of things you can do just to build up that distance between your feelings when you have the thought and the verbal form of the thought: visualising it on a screen, saying "thanks Mind!" when the thought pops in e.g. recognising it's just a thought, doing mindfulness practices etc.
It's powerful stuff and has a decent research base, including for OCD I think.
TeaCup, do you know what caused your relapse? Will you get CBT again?