Shaking things up

Did some shaking at the physiotherapist's, on music. Previous time, I declined, wasn't feeling up to it, but today I felt sort of neutral.
"Are you feeling good or bad?"
"Uhm... neither, actually, a bit in between."
"Is your body tense or relaxed?"
"Uhm... well, both, sort of, not especially one or the other."
"Are you feeling sad or happy today, right now?"
"Neither, I'm feeling uhm, neutral. If I wasn't I'd tell you." (I would, I'm quite sincere.)
I thought about it out loud for a minute, saying I might be in that flat place in the down-position. Sounded nonsensical so tried again.
That moment right before you inhale; you don't have any air left, you're all done exhaling and your body is getting ready to inhale. The mental equivalent of that moment.
At least, when I said it, I hoped that would be it, that really deep and dark place from where I could only be going up. But I'm guessing it's not that, judging from how I feel right now.
Shortly after shaking my body for twenty minutes, and after we talked a bit, anger started to surface. Yeah baby, that's good, go with it. But it was more like a knot in my stomach, tense and sharp. Felt like it could grow into flat-out rage, that's why I wanted to write here early in the evening instead of early in the morning, as usual. Grab it while it's hot.
Maybe I shouldn't have done other things online first. Oh well.
I feel where it is and what it is, so I'm going to push my own buttons.

I know it's to do with people taking from me whatever they want, because I won't mind, I'll be okay with it, I won't speak up, I'll go along with anything. Since I'm not a strong personality and I won't make any trouble if you take advantage of me.
In fact, it's not even taking advantage, since I'm going along with it, approving it in a pathetic, docile way, that's how I was taught. Just go along and shut the fuck up. Don't even think about speaking up. You have no voice. You have no voice in what's happening.
Just go along with it, you're just not important enough to take into consideration. You understand, you're a good girl, a smart girl, you understand why it's too much of a hassle to include you and your opinions in what's going on. We can't be bothered, it's so much of a burden to raise you as it is, you're so much trouble, such a difficult girl to deal with.
Just shut up and take what we have to give you cos it's all you're gonna get anyway. Ungrateful shit. You should be grateful merely for being alive. You're nothing you know, you don't deserve to live.
You're black inside. These are actually my mother's words, what she said to me in a resigned tone of voice, which made the impact huge and unforgettable. Not in a good way. "You're black inside."
We put up with you, so we can do whatever we want.
You deserve every bad thing that's ever happened to you.
You'll never be good enough.

Ouch. The knot is quite painful, and strong. If I could just use that energy, use that anger to eat my fears, like Packman. I'm not sure what to do with it now. I can get it to surface but then I don't know what to do with it!
Maybe I should use the punching bag in the shed. I don't know.
Is there something else I can do? Something useful? It must be good for something, it's energy.
Aw man, it's painful. It's physically hurting me. I think I'll try the punching bag, and maybe I'll get back to it later.