OP is basically trying to get his brother kicked out of college, fined tens of thousands of dollars, and sent to jail.

Now that my dad's gone, to me it makes sense that my mother, who is actually kind of well off now, should take on responsibility for my brother's loans and financial aid.

OP: Let me involve myself in something that I am not involved in.

I hoped to talk to my brother's financial counselor and be transparent

OP: Please, PLEASE, PLEASE let me get involved in something that doesn't concern me. I need to provide evidence against my brother before talking to a lawyer. If I don't tell them and get him kicked out of college, who will?

I hardly understand anything about this situation

....

I want to help my brother, but if it involves me lying, I don't want to.

I myself have just been brought into this mess and know very little.

It sounds like you involved yourself, you got in too deep, you found out something you didn't need to know, and you're the type that shouldn't know that type of information. Ignorance is bliss. Go with that.

In the future, stop putting your nose where it doesn't belong. Concern yourself with your life, your problems, pay your taxes, and go to bed early. You don't want any part of any of this.

tl;dr In the future if you feel the overwhelming need to tell the truth, talk to a priest.