this is a great topic that i too have encountered. I am a buddhist, and I have found that after meditating for about 10 years now, that i pick up on peoples energies, both good and bad. I have encountered this same problem person that sends out the most violent anger energy towards everyone, and no matter how much compassion you generate towards this person, you still feel the negative energy just entering into your chakras and what feels like your body. I even tried to just let go and absorb the energy while visualising the person in a happier mood, but it did not work. there anger just overcame them after a short period of time. i tried mantras, and eveything. but still nothing; then i came across a friend who practices chi energy work, and she informed me of a very powerful technique that can be combined with the compassion visualisation, to block anothers negative energy from being destructive to yours.
in martial arts you hold your arms out straight and visualise the prana, chi, or whatever you wish to call the life force energy of the universe, as an unbreakable solid force,like an a steel solid ray of light unbreakable. an infinite ray of light. this is the force that martial artists use to break boards with there hands, but for the buddhist, just imagine this unbreakable energy coming from your center, and extending to infinity. nothing negative can penetrate this light, and it isnt destructive. this force makes the flesh of martials arists unbreakable. it is the same light we see in meditation used in a different way. all good energy may come and go, but all harmful intentions and energies are now blocked.
the energy that is extending is not harmful to the attacker, it just blocks out any negative energies or intentions that the attacker is emanating towards you. now at the same time visualise compassion towards the person.
when i was getting daily attacks from this individual, it felt like my heart center was being crushed and i felt the exact same symptoms as you. I have been practicing this technique whenever i encounter this person, and it has been working. it takes a little practice, but it does work, and is peacful in nature.
a final note, there is a difference bettween this type of person, and the usual angry person, the attack for all those who have never experienced it, is a form of negative energy attack. it is literally one step away from being a physical attack. It is much different then just an angry person that can be tamed with patience and compassion. when you have no choice but to deal with this person one on one almost every day, then you should generate the field of infinite light for your own well being.(and theirs) you can have compassion for them, and they can be angry, but they have no right to violate your personal energy center or happiness. Unbalanced energy in the body throws off everything else, and causes your whole system to be unstable. especially when you are striving for there peace!