I had to stop taking HRT ...
I saw a herbalist for a while and that really helped, turned the dial down, most importantly stopped (those cortisol) waking up at 3am every night with a sense of overwhelming panic / dread. She made a special mixture for me, so not exactly a supplement.
I also took CBD oil for a while and that seemed to have a positive effect, although it was pretty limited.
I'm a fan of herbal tea, and Valerian works for me.
And this might sound a bit ridiculous, but my mother used to swear by Floradix (it's an old fashioned iron and vitamin liquid, a bit like a tonic, no constipation for me with this) and I really do think it works ... Literally no scientific evidence for this, but I believe that it lessens fatigue and so I don't need as much adrenalin to get through, which in turn means it reduces my anxiety.
Nowadays, if I feel as if I need a bit of support, I reach for the Floradix and Valerian tea (the stuff you can buy from the supermarket labelled as 'Peace' or 'Relax' seems to work for me, although I also make my own with Valerian, Damiana and Lime Flower). These are definitely the cheapest and easiest options.
I should also say that I see a good massage therapist once every couple of months and I've been in weekly therapy for over three years, so yeah, I can't really disentangle what's having what effect.