Sometimes we're stuck with our thoughts and it feels like our minds move 100 miles a minute. I notice that that tends to happen when I drink too much coffee or don't get enough sleep, especially when it's a few days in a row.
But what I do notice what's helpful is sharing this with someone else, particularly someone that understands what it's like. It's not very validating when someone says, "What do you mean you're feeling that way? Just be happy." We all want to be understood and to be heard. Or worse than that response, "What do you have to be unhappy about?"