I think as horse people we can really compartmentalize our “horse life” from the rest of our life, and don’t see how stress or anxiety in one part of life bleeds over into the rest. I have definitely found that when I’m particularly stressed about work or relationships, it shows up in weird ways in my horse life — often anxiety about horse welfare or nerves in the saddle.
One exercise that helped me in the past when I got a nice horse and was feeling overwhelmed was to remind myself that it wasn’t all on me — the horse and I had a whole team supporting us, and I could ‘delegate’ some of my worry to other folks. For example, if there’s been a big change in the weather and you find yourself at home worried your horse is going to colic, you can remind yourself that your trainer, your barn manager, and the barn staff are all worried about the same thing, are there at the barn with eyes on the horses, and they will call you and the vet immediately if anything seems not right. You are not the only one who cares about your horse - trust and lean on your support team!