In my view you did not quit, you took responsibility for a situation were the other part did not.
To make things worse,...
Even AFTER this act the other party did not take responsibility (by opening discussion, by understanding "stopping a scene" is a very emotional thing for a sub and that aftercare should sure be provided then).
You basically learned that this dom is not up to the tasks he is handing out and it is very smart not to opt for being the guinny pig in that.

As wedgiebondagebabe is saying, many are new here. Many have to learn. Doms may think that overasking defines the real dom.
Soooo,... mistakes happen. Subs shall keep an eye on their safety knowing all that.
It could have been ok, this dom could have learned from this. The way it looks now is that YOU learned but the dom didn't.

Do not feel bad for quitting. Granted there might have been a couple steps in between, but you are just as responsible for your safety as any dom.

There are a lot of people on this site who are learning. It is up to you to research and know things to. In fact I think that is where my dom side has helped so much in realizing what I want to undertake for my sub side. It doesn't matter which side of the play you are on, you have to feel safe and respected. And if that Dom doesn't want to listen or be there, then there is nothing wrong with quitting.

As I have said over and over, the other part is communication. It's how you know you have done all you can do to express your mind. If they still don't listen, then again kick them to the curb. If I didn't block people, or I let people boss me around, I would not be happy and I would have left this site a long time ago.

I wish you good luck finding a play partner who treats you the way you deserve to be treated.

Sorry you had such a rotten situation.

Keep these items in mind when perusing future relationships:

SAFE

SANE

CONSENSUAL

Those are the three pillars of a good D/s relationship. If the Dom(me) can't give you save tasks, then that Dom(me) has issues and there is nothing wrong with you backing out. Always use a safe word. Each side should do their research. Trust is earned. And, ideally, a Dom(me) or task giver shouldn't give out a task that they would not be willing to do themselves. Ideally, they should have experienced the task themselves and also keep in mind that different people have different thresholds. Start light on tasks and slowly work up so that thresholds can be judged.

... Sorry if I'm rambling. I'll shut up...