I have known quite a few people who get so psyched up to get healthy by lifting weights and training in other forms that they end up doing nothing. There are indeed some people that need to smack themselves or ram their heads into a wall to get psyched up, but for many people that can have negative effects.
Raising your blood pressure to high before you workout can zap energy and even put you in danger. Warming up your muscles and getting your heart rate into a proper zone is fine, but that should never raise your blood pressure to a high level. Also flexing too hard or for too long will zap your muscles of the energy they need, taking away from your actual workout. Long story short: ATP is energy when for your muscles, and if you strain for too long you use up your ATP. If you do not have it when it is time to lift, you are robbing yourself of a good workout.
Psyching yourself up can often be done be conjuring up names and faces of those that anger you. I have pulled good amounts of weight on the deadlift doing this, but I noticed that I was completely useless after about thirty minutes of activity. A rush of anger can be good if you need only a burst of energy, but for anything long-term (1 or more hours) I suggest letting the anger go. Besides, the gym is for letting go of the anger, not letting it continue to consume you.
Psych yourself up, but do not psych yourself out for a workout. Remember that a warmup is to get you warmed up, not to get you burnt out. If you have anger you are dealing with, let it fuel your workout, but do not let it burn you up all at once, or you will not get the most out of your workout.