Exercise
Mindfulness Meditation
But the biggest thing by far seems to have been from sorting out my gut. I have been working in the tropics on and off for 20 years and have had various parasites and infections requiring harsh antibiotics and other drugs and was fairly convinced that I had something akin to "Leaky gut syndrome".
I took it upon myself to eat more fibrous food or take prebiotic supplements and as far as reasonable avoid sugar and alcohol (but without being puritanical).
Bimuno really helped as did starting on inulin and psyllium daily, my overall health has improved anyway (gall bladder issues were in the mix as well) but I also one day realised that the constant nagging anxiety that I used to have has all but disappeared.
I still get anxious, but now it seems to be more of an appropriate response to circumstances iyswim? When I look back, my anxiety very much was centred on my body rather than my head of that makes sense?!??
Also, if it does come back, I find it quite easy to correct by getting my diet on track. The Michael Mosley book adds quite a lot of weight to this.