Thanks for your message. I was not talking specifically about ACT but yes I agree that it is an attractive approach and I hope to learn more about it myself as well. It sounds like trying to reincorporate those skills in your life has promise. If you give it a try I would be interested to know (if okay) how it goes.

One response to intrusive thoughts that I like is "<sigh> There you go again." The idea being that these thoughts recur (<sigh>) but one is not going to allow them to bring about a struggle within the mind; rather, one just sighingly acknowledges their presence and proceeds as best one can without engaging the thoughts.

Do you know the poem The Guest House? The approach is slightly different but I thought it might interest you:

The Guest House

This being human is a guest house.
Every morning a new arrival.
A joy, a depression, a meanness,
some momentary awareness comes
as an unexpected visitor.
Welcome and entertain them all!
Even if they are a crowd of sorrows,
who violently sweep your house
empty of its furniture,
still, treat each guest honorably.
He may be clearing you out
for some new delight.
The dark thought, the shame, the malice.
meet them at the door laughing and invite them in.
Be grateful for whatever comes.
because each has been sent
as a guide from beyond.

-- Jelaluddin Rumi,
translation by Coleman Barks

What other possible ways might you consider to deal with intrusive and unpleasant thoughts?

I wish you a good day, as best as possible while in the hospital.