What are good tips for dealing with anxiety? I find heavy or controlled breathing makes it much worse.

Anxiety? Anxiety is very common and there are medication and therapy for it. But medication can be habit forming and r intended to be taken on as needed basis. I believe cognitive behavioral therapy can be a very good to help u deal with u negative thoughts and when needed u can add medication.
Anxiety. Any activity that helps you relax is good for anxiety. Meditation is one way where you lie or sit comfortably and just pay attention to your breathing. Don't speed it up or slow it down; just watch how it goes on its own for 10-20 minutes. Progressive muscle relaxation exercises are another way. Tighten up you face mucles for 3 seconds, relax, do it again, relax, then your neck muscle, etc.