There should be (from what I have experienced, though it seems others do not have this feature) a way to turn off the overstimulation and sensitivity mechanic under 'Difficulty settings' in the options screen of the main menu. There does not seem to be a way to completely overcome overstimulation without just flat disabling it.
The Lube item can be used during (as a dom) or before encounters to decrease overstimulation gain, but it is not perfect by any means.