Definitely, CR.

ACT is a lot about not judging and labelling feelings as "good" or "bad" and not fighting to get RID of challenging or difficult feelings. It's about noticing them, allowing them to be, allowing them to pass in their own time. It doesn't mean never taking constructive action (like going for a walk or listening to calming music) but it's about accepting that ALL feelings are okay and not inherently something to get rid of or "fix"...

I had to do years of CBT (and make some progress but still struggle a lot) before I'd consider such an approach, though... I can't imagine still fighting to change all the challenging feelings - so draining and like smacking your head against a brick wall!