Hi, I'd like to help you with your question.
It is actually very common for people to feel the way you do. Some hide it well behind masks of arrogance or indifference, others decide they are going to be self centered and not care (that way they don't get hurt first), and still others, like yourself, feel it strongly and are often hurt. It is the people like you that have the most sensitivity and selflessness with others.
It is alright to feel hurt when others treat you badly. Almost everyone does. The difference is how you react. You may feel like you have no defenses or you may chose to not have any defenses and therefore you feel rejection much more strongly. That is ok. But what you might want to change is how you react.
Acting mean or hurtful back is only going to be against your nature and therefore make you feel worse. Plus, it will change the other person's perception of you which you probably do not want. What you can do is see other's for who they really are. Most people who act out in mean or hurtful ways are hurt themselves. They may not come across that way, but if you think about it, there is no other reason to be hurtful to others except that you are hurting yourself. The person may be afraid they will get hurt or they already have been terribly hurt so they lash out each chance they get.
Accepting that you are a kindhearted person and that you are sensitive to others is a good step. See yourself in a good light because very few people are like you are. When others hurt you, remember they are acting out because they don't know a better way to deal with their feelings. So it is not you they are reacting to, but their own hurt.
Also, work on your self esteem. Educate yourself about how to increase your esteem. Read, consider therapy, and talk to others who do care about you and understand who you are. Ask for insight and help.
Here are some resources to help get you started:
Self-Esteem: A Proven Program of Cognitive Techniques for Assessing, Improving, and Maintaining Your Self-Esteem by Matthew, Ph.D. McKay and Patrick Fanning
The Self-Esteem Workbook by Glenn R. Schiraldi
Healing Your Emotional Self: A Powerful Program to Help You Raise Your Self-Esteem, Quiet Your Inner Critic, and Overcome Your Shame by Beverly Engel
You can find these books on Amazon.com or your local library may have them for you.
To find a therapist, talk with your doctor for a referral. Or, if you attend church, talk with your pastor. You can also search on line at:
I hope this has helped you,