Hello Amber !
To me, the most efficient is to take a good detective novel, easy to read but super interesting, to forget everything around me. Also, it can be super efficient to simply eat things you like, for example your favorite dessert, something like that. Go see the horses can be a solution too, but when I am stressed out or angry, or feeling bad, I just visit them but I don't ride, in order not to pass on my stress or my frustration to them. When you feel bad, you generally ride bad and feel worse after I think.
For me I watch Netflix and sit with my dogs just simple things really
When I feel down I always go to the gym or do a workout at home, it cleans up my head, I don't think about anything else and after I feel so good!
When I am in one of these moments, I think about the things I love and do things that usually cheer me up or at least make me thing about something else: cooking, visiting an exhibition, shopping, reading, watching my favorite show...
Good luck I am sure you will be fine soon x