I get the "backwards relaxation" thing going on sometimes, but it's so sneaky, it's hard to notice until I'm really tangled up. If it's negative thinking that sneaks in and distracts you, try consciously following up or replacing each negative thought with a positive one. For example, "Wow, I'm trying to relax, and it's just making me feel more anxious!" gets followed by "Yes, I'm trying to relax, and that's a good step for me. I used to not be able to practice it much at all, so I'm improving" (or whatever you can think that's a positive rather than a negative).
Focussing on being in the moment, especially the way Gill describes is a good distraction too. Sometimes, that helps me nip an anxiety attack right from the start.
And, Gill, congratulations on 3 days! You go! That is just such a huge step, taking one baby step at a time!
Co-Moderator, Anxiety and Panic Forum