I think all males feel like that - I certainly do. It's your body's way of telling you to take a break from sex for a while; it operates mentally as well as physically. Medically it's called the "refractory period"; the length of time before the body is able to have another orgasm. But as you say, one's entire psychology is affected.
Since the male sex drive is so strong, it's fortunate that this happens; otherwise we'd never be able to get on with the rest of our lives!