Long-time occasional anxiety sufferer here.
Some of the things I have found that really help: regular exercise, as already noted by other posters - chemical effects, but if you feel in shape, it lifts your whole self-regard;
Diet is super-important as well though - caffeine, sugar and alcohol really are toxic, even if we all like to indulge. I actually did a
treatment for candida infection because of eczema/psoriasis, but it's amazing the beneficial effect that it has had on my mental/emotional state also. There is an increasing amount of studies out there linking gut and mental health.
See also, meditation (the Headspace app is great) and
breath-work can be really powerful as well (I'm actually training to teach the latter right now on the side).
I wonder if any other folks on here have tried coming at it from these angles and how they got on?