Hi, you have described me perfectly. I wish I knew a way to turn all the worrying and feelings off when I get so overwhelmed. I do what you do, I just go numb when I have had enough and my body and mind can't take it. When it really gets bad my eye will twitch, it's like I have short circuited.
I know there are coping skills like meditation, but knowing what I know now about HSP, I think this is who we are. One thing I do is try to avoid people or things that might create turmoil in my life. Find people who are low drama to be with. Don't overreact, give yourself a day, sometimes things will look better in a day or two.

I do find that getting some time alone can energize me so that I am ready to face the next day. We really do need to always take time to nurture ourselves.

Well, I struggle with this also, but I can share a few things that have helped me to varying degrees.
One is that someone once told me that when people behave badly it can simply mean that they haven't reached the level where we are yet. Sort of like a toddler who grabs your candy from you. They are several layers of learning below you. That helped me a lot.
Also, someone else told me that when others hurt us, it is really the pain they have inside seeping out. As in, they have so much of it, it leaks out and we just happened to be "in the way."
That helps to a degree, but, then I get hung up on "but what if it was a situation where they really were angry with ME and I aggravated them?" Like, when it seems very obvious that they just plain old don't like me.
So, then I try to revert to thinking about how everyone is imperfect. The world is imperfect. Relationships are imperfect even when they are good. So, I can't really expect every encounter I have with others to go perfectly, realistically.

That helps, but I still struggle a lot. I guess you could call that "toning down my sensitivity."
One last thing is part of my faith. In my faith (Christian), I can pray about it and let God handle it. That's the goal anyway. I can pray that he validate/convict the right/wrong parties and be willing to be on either side and I've been often surprised at how this results in God making things set to right.

Yes, the world is imperfect. Also there's the irony that we can't appreciate the light without the dark. I was in a relationship in the past where my partner enjoyed bullying me. Bullying, in my opinion is a result of insecurity about oneself.

Darkness, my ex bullyed me. I know it gave him pleasure to hurt me, You are right, I believe he was insecure and also felt inferior to me, so it made him feel like a big man to take everything out on me. Unfortunately, because I am a HSP, I would get so overwhelmed with emotions, I could not stand up to him. I was an easy target. I don't think he ever held me or showed any empathy when I would cry. That was the ultimate high for him to make me cry......what a sicko. I am sorry you were also a victim of bullying.

Maybe something like meditation would help, as it gives you control over your body, mind and emotions. Breathing exercises too, or stretches. And simple knowledge about yourself - when you need to stop and take time out, spotting the signs early and taking action.

A while back I read about the 'spoon theory': http://www.butyoudontlooksick.com/wpress/articles/written-by-christine/the-spoon-theory/ You just need to know when you are running low on spoons, or what activities use more spoons than others for you. It is different for everyone.

And similarly to what others have said, appreciating that others have their own experiences and reasons for saying and doing things, most of it has little to do with you. That doesn't mean they are somehow less evolved or bad people or worse than you. Just that they have had experiences in their lives they may not have come to terms with, sometimes they may not even be aware of this.

A good book to read is Anthoy De mellos "awareness". A lot of sensitivity is ego centered and De mello argues there really is no such thing-the ego. Short book but a real leap rather than most psychology which treats one ailment by giving you another.

Darkness and Quietpoppy,

I too was in an abusive relationship. My first real boyfriend in college was very cruel--mostly emotional, but a little bit of physical abuse as well. He often tore me down for being too "thin-skinned" and often told me that he wanted a girl who was more aggressive than me. He ended up cheating on me with someone who was apparently "more aggressive." Like you, quietpoppy, I could not stand up to him either--I was unprepared for what to do and I thought I loved him. Now, sometimes I fantasize about going back in time and standing up for myself with him and dumping him...but I know we cannot change the past. My ex enjoyed making me suffer and once we broke up, I refused to talk to him even though I think he still wanted a friendship...but interestingly, it was this experience that led me to read Elaine Aaron's book: "The Highly Sensitive Person in Love" and then I discovered was an HSP.