that was a long read..
How old are you?

i dont think you where wrong and even after you lost your temper and hit him he actually egged you on to carry on.

i was exstreamly depressed during my early teen years due to bad acne so if you have no idea what your talking about dont run your mouth calling him silly for being depressed. 

he called him silly for blaming him hitting his stepdad on depression from acne

That's pathetic. I highly doubt you could go what I went through. In fact, knowing what I went through I'm positive you probably couldn't go through it. I won't say you can't because you have never been in that position but coming from someone who dealt with it and constant suicidal thoughts, I know how bad it was. Notice I specifically said horrible acne. Cystic acne to be more precise. It wasnt a few pimples. It was bad enough to destroy my self esteem and make me completely secluded from nearly everyone. 

I would like to add just two more things. One, I never expected him to hand over the car for nothing nor asked him to. He approached me once about buying from him which I said I'm not sure because I didn't have the money then and i didnt know they wanted to sell it so quickly. He never even gave me a heads up when it was sold, I found out when I heard some guy coming over to pick the car up and that was it.

He didn't say a word till me until much later on when both he and my mother knew I was upset about it. If I had to I would have at least give them something but it's bullshit anyways when they say they need the money only to spend more of it on another car. Secondly, some of you seem to think I have it out for him. I won't deny I don't like him but at the same time we were close and it's a love/hate relationship. I had reasons for my treatment towards him for how he treated me at times.

My sister mentioned to me earlier that my mother and him could break up over this. My mother can do as she wants and I will tell her that the next time we talk but I will also tell her I DON'T want them breaking up over me. If it's been brewing (they have had fights but I cant speak for their relationship) and it's what she wants fine but I won't cause a rift between my sisters, my nephew and even our pets as my mother and him him take care of them for the most part.

Occasionly I feed my dog, cat or turtle if need be. This it out of routine because my mother feeds my cat in the morning as she wakes up when she works, he feeds the dog during the afternoon and he feeds our turtle. I used to feed him but Eric told me he will take care of it and I left at that. 

Especially because I know he greatly cares for her and I won't have it end just because of me. 

I never once I blamed bad acne for hitting my step father. Where the hell are you getting that from? I take full blame for it but he had it coming for all his bullshit. I don't say he had getting beat up coming to him, though I tried stopping several times and he wouldn't fucking leave it alone or at least tell me to stop and no more. 

So what are your plans for your future now that you yourself have concluded that it wasn't the best thing you could do? Study? Work? Be out of the house for at oeast 8 hours a day? Talk to the guy? Say that hes great for your mother? Other plans?

Cystic Acne is horrific. Everybody deals with pimples but Cystic acne is just overboard.

horrorfest you may have already answered this but what is your age? I see you mentioned your teen years in the past tense so I'm guessing early twenty's.

I would recommend setting some boundaries with your step-father. talk to him politely and explain your frustrations and let him know there are certain things you are not ok with.

In addition, if you are in your early twenties I would recommend looking into getting your own place, it can be difficult at first for costs but I think you'll find you can adapt and the challenge will make you more self reliant and less dependent on others.

At this point it doesn't matter if it was right or wrong to fight with your step-father the important part is moving forward so it doesn't happen again.

Well after doing a google search of that condition, I do apologize for being quite critical of your depression due to acne. 

But, I still don't get the need to mention it in this thread. 

Dude, so fucking what if he broke his word? My parents break their words all the time and  I sure as hell don't beat them up or even get mad.

The real question is, what do you do for him? Have you ever wondered that? Do you cook just for him? Do you buy him presents? How do you show you appreciation for everything he does for you? Bringing money, making food, and most importantly helping you out when he doens't have to etc.

And again, you use the word "harassing". What do you mean by that?

Since you're 20, I suggest you get a job and stop expecting things from people. I deally, you need to see a professional. Beating a person up, because he's "harassing" you is messed up.