My heart rate gets so low…what the heck?

While I’m resting, like really resting, like laying down in bed for many minutes resting my heart rate will get down to the mid 40’s. I never get any Apple Watch alerts or anything. I’m terrified at how low that is. I don’t have any weird symptoms while it’s that low, no dizziness or anything. But it’s still scary to know…man my heart rate gets low. And then in the rest of the day I’ll get up to 150 just walking across my house 😭 there really is no middle ground here.