Cold Heart or just sensitive?

I, at the age of blahblah, have realized sooo much about myself in the last year. I am sensitive. I had to say it, own it and admit it.
While I know I can be grudgeful, it all stems from sensitivity and being hurt. All my life I lived for others. My sole purpose for working when I was young was to help my mom financially. I put myself last for others, follow the rules and always do what is asked of me, but as of recently it just started to pay off.
I have prayed about my ways. If I feel mistreated or abused, their is an evil me inside. No I won't hurt you, or talk about you. But Lord forbid you are lying in blood on the side of the road, I will pull over, take a look, make sure you see me, and take off! That's what my heart feels, or felt at least.
I know that I am easy going, easy to talk to. Never had any trouble with anyone in school or work. Like by everyone. Didn't start to engage in arguments until I got married and now that has even changed for the better. So for the life of me I can NEVER understand why someone would feel the need to lie to me or mistreat me. It hurts to think about it.
Hubby says it's those exact reasons I've listed that makes people afraid to hurt me. They will lie to stop from hurting me with the truth. That might be true in some cases but not all. I bend over backwards for everyone I know and never feel I get it in return. so it has left me bitter in some areas in my life. I pray about it and it's better.
Am I sensitive or cold hearted?