Is the length and intensity of feelings and emotions limited? So, I know hormones in the brain being released are more or less responsible for the emotions we feel. From a physical point of view, the amount of hormones available and the production rate of the hormones is limited. So, if the amount of hormones being released exceeds the production rate, from a purely physical point of view, at some point it will be depleted. I personally experience this in the form that after euphoria I feel more down than usual (at least I believe that this is an example).

(Also, there is physical pain. I have no idea if that can be limited in any way depending (or not) on time of duration and intensity.)

So, I can grasp the concept from a logical point of view. On the other hand, I have a strong sense that there are certain actions in the world that have no upper limit of inflicting physical and psychological pain.

Question: Is the length and intensity of feelings and emotions limited, especially these of physical and psychological pain?
The key terms to help understand the answers about the duration and intensity of experiences over time would likely include habituation, emotion, and pain. You might be surprised by how scientists use these terms differently than most people. Consider an intro psych textbook or wikipedia.

For example, emotions are generally defined as being brief, transitory affective states. If someone has a negative feeling that lasts for hours, psychologists might call that a mood. If a person has a negative feeling that lasts for years, psychologists generally use other labels such as personality. The experience in a moment might be the same between these cases.

There are some assumptions in your question that are not shared by most research or clinical psychologists or neuroscientists. For example, emotions aren't deterministically caused by hormones.