Well, this is going to be a long rant. Needless to say, hit the view thread button to read all this.

I'll start at the beginning, just for a better understanding.

I was born a bastard child, where my father left my mother and I alone. He was making millions, a head of a company now where he sells Medicare and Medicaid equipment to hospitals and such. Needless to say, it's a lucrative business.

Every month the only reminder I had growing up was the check that came in the mail to help us stay afloat, with our income typically around $17k a year. (Not including the child support.) We've mostly lived in the same apartment complex for as long as I can remember, escaping poverty in Irving for a better life in Dallas.

Now, don't take my mother for a saint. To give some background on her, she only finished high school, and went on to belly dancing shortly after that. (Like I said, bastard child here). During my childhood she dragged me around with her, becoming the authoritarian parent that I know her as. Whenever I did something wrong, 2 things would happen.
1) She would verbally yell her hatred for me.
2) She would beat me with a broom until I managed to escape into my room, often having no food until the next day, regardless of what time of the day I was caught doing something wrong.
A few years passed by of this formula. Eventually she switched to verbal insults, since she knew I was stronger than her at this point. (I won't go into detail of the verbal abuse from here).

Eventually she settled down, and laid more responsibility on me, as it comes with age. I typically spent most of my days alone in the house, finding solace in reading and video games, an escape, if you will. Needless to say our financial situation didn't improve, actually, it got worse.

We had to file unemployment a few years ago, man, that was harsh. People would always look at you funny when you were using food stamps in stores instead of actual currency. Anyway, we eventually came out of that debt, (thank you government!) and proceeded on with our lives.

Fast forward a few more years to today. A few days ago my mother came to inform me of some rather interesting news. Now, with college, I had no way to pay for my tuition, despite my scholarship. However, my mother told me that she had been keeping in touch with my father for an unspecified amount of time, saying that my father would like to help with my college funding. Soon, there will be a $3,500 check in the mail that will come twice a year, which should just cover my tuition, as long as I keep the scholarship.

Here's the interesting parts though:
1) My mother had been keeping this a secret from me on purpose, even though it was my father she was dealing with.
2) My father, who I barely even know, suddenly wants to help? Why?
3) My father's wife thinks me the bane of her existence, wishing to get rid of me as soon as possible. Any emails pertaining to her, and not private to my father, have been spiteful, cold, and curt.
4) Apparently I have a sister in-law. Who knew?
5) My mother won’t let me see the emails until the check comes in the mail.

So, my question is, how do you all think of this situation? Personally I feel like it seems too much like a framed movie, to be honest.
I am mad at my mother for keeping something like this a secret from me for all this time, and not letting me even see the email.
I'm mad at my father for not being there.
I'm grateful that my father wants to help out.
I'm sad that my mother-in-law hates my existence.
And I'm somewhat happy to know I have a sister out there, even if she may not know about me.

What do you think?

I know that spewing a cliche right now is really, really, killing the mood, but we're not so different, you and I.

I had a background much the same as yours, sans the abusive mother(because she wasn't in the picture either!). I actually ran into the same set of circumstances a while back and what it all boiled down to is this:

My father grew remorseful of leaving my sister and myself behind and tried in vain to take a few steps towards bettering our relationship. My mother had kept in close contact with him because he genuinely wanted to be a part of my life, but she didn't want him in the picture.

I'm not saying this sort of thing is the same as what you have going on, but it sounds startlingly similar; even down to the "Surprise! You have a sister!" part.

So, my two cents(for what they're worth): either your mother was fearful of what you would do when she told you about your father wanting to be involved, or she was planning on keeping those tuition checks for herself.

Either way, give your old man a chance, at least. I know, and believe me I do know, how hard it can be when confronted with that sort of situation, and I also know that nothing can repair the damage that's already been done, but he might end up being genuinely concerned for your future after all.

>>1 Ah, this is quite the situation you have here. Personally, I enjoy life having a bit of flair to it, even if it is pointed towards me. Maybe I get a sick obsession of being the enemy of the group, the odd man out, the outcast. Or maybe I'm just too damn impressive.
Needless to say I think Feral would have a better impact of advice than you, since my family is sort of average, despite my relationship with my girlfriend's mother. Actually, now that I look at it, I'm in the same boat as you, but with my girlfriend's family. Sadly, I don't intend on giving her up, so I'm stuck with them.
Jeez, I digress a lot. Abyways, try your best to sort of flow through the situation. It seems like your step mother is only spiting you because of fear that you may have a certain grudge against your father and will try to squeeze out as much money as possible. A women who only wants the necessary funding to keep her family happy, as well as her own satisfying needs.
Your father, now that could be a number of reasons. Maybe regretting to have left you and your mother in the dust? Or perhaps a true change of heart and he's trying to amend things. Or maybe he's expecting to et something from you in return.
Your step sister is rather an interesting bit. Maybe you could piss off your mom a bit more by hanging out with her? Or maybe she wants to know about you, her one and only step brother. Who knows? That's for your to decide, as per the previous advice given to you by Feral and I.
Nevertheless your ultimate goal should be to just stay low and keep your head from getting blown off. Lastly, just watch the sparks fly~