Sinking

I feel like I'm sinking into depression. Yesterday I got into an argument with my mom because I don't agree with how she treats her stepson. I feel that she's pretty much an evil step mother. Her husband is allowed to not have control of his emotions and himself and throw man fits - throwing shit, slamming shit, banging shit around, swearing, and threatening others.... but she expects this ten year old child to understand his emotions and handle himself properly at all times or else be punished and threatened. I don't understand it. Her excuse for her husband is, "That's all he knows Rachael - he's trying!" And I'm like, "Yeah, and this is all your stepson knows too, it's all that's been shown to him. Difference is is that your husband is a GROWN man and your step son is a CHILD." It's fucking bullshit. So yeah, we argued when she was bitching about him to my grandmother. I told her to stop her bitching and HELP him grow or stop her bitching and leave him alone.
Anyways - the other day my bank went into the negative because my account overdrafted by $3 - I got charged $40 in fees. FML. And so - I went to check my cell bill today and because I shifted the day I could pay from the 1st to the 9th then I got a hefty charge fee and now somehow owe them $300 when my normal cell bill is about $120.
On top of all of this Lailah's birthday party is coming up in a couple weeks and I need to pay for the whole thing - ice cream, cake, pizza, and goodie bags. Blah.
And today I got offered to be in a co-op to order Cloth Diapers for discounted prices. If I were to get 30 diapers, 2 wet bags (what dirty diapers go in while outside the house), and 2 wet pails (like laundry bags) then it'd cost me about $150 before shipping charges and paypal fees. But that's a DEAL since I'm spending over $100 a MONTH in diapers atm. Cloth Diapers wouldn't need to be replaced. Just washed. So I'm going to ask my grandmother to borrow the money tomorrow.
My most recent plan for my future was to go to casino dealing school and get a job working at the Texas Hold Em tables at a casino - but I checked all 3 casinos around where I live and none of them are hiring right now for any positions I'd be able to get - even with the schooling. So, that would be pointless to waste money on - the schooling that is. So, that's a failed plan.
My next idea is to get my psych degree but that's at least 4 years in college. And I believe I could get financial aid but I don't really know if it would truly help us live like I would need it to.
I don't even know what to do or where to go from here. Yesterday I just cried - literally, about wishing I could commit suicide. But I can't - because I have to be everything I possibly can for my children. I have to become someone, something. I need to figure something out and succeed  -  for them. But right now I just can't seem to figure out how.