How to cry in anothers presence when hurt?

I have been know to cry around an awfull lot of people…like when someone makes a really really offensive remark or something that remains in my thought for a while or when I’m under too much stress..NOW A DAYS its usually related to my missing home and hoping to be treated with respect…sometimes I cry when I listen to a touching song (not about love or nething) but many a times songs with a highly charged tune that takes you back to your old liivng… like my home(friends,family,lessons learnt in life etc)-some not so good while some of which are really joyous accounts of my life…people who know me always laugh at my jokes..such form of response is something thats really natural ,but they never understand what really goes through my head…usually after such positive responses I’m drawn back to thoughts where I’m reminded of some comment made in the past… so even if I crack a joke and get a huge positive response..I still dont seem to get over that( past) remark and usually if I cant get it out of head, I get highly emotional..and I start sobbing then and there…this has happened to me a lot of times..back home and on some occassions in the current college im at…Another instance of me crying around others, WAS when I used to get hit(usually a non-ocurent act) by someone who is older, andnomally of a significant influence among his or her friends…this has sadly occured with both sexes and that is what makes me believe that I need to control the way I react to such aggressive and unruly behaviour on part of others… what is most heart wrenching for me is that as I cry ,I somehow try and defend myself at all times during such occassion…Based on my past accounts with people who behave negatively towards me, I often react by defending my self using words and sobbing at the same time…and this is what’s really awkward ,cause I never resort to means of violence(I did sometimes react volently in the past when I was a kid but that too was really contained, and was meant as a sign to others, to stop messing about) However in a majority of such occassion, I have always used words and emotions as a form of expression when im defending my position…this is the only why I know, how to defend my self during such times…is this normal or is it jsut me?