I'm sorry for your loss. You have a long and frankly scary road ahead of you.

1) From the sounds of it, you're now the parental figure for your little brother.
1a) Make sure you try and pass off the things your parents did for you, taught you, and show how much they loved you both. I agree with many of the posters suggesting you take time off to spend with him. Let him get used to you, get to know his routine, get to know what it's like to have a kid, etc.
1b) Once in school a live in nanny is also a fantastic idea which would be worth the money. But seriously take that time off before school because you need it man. Also an apartment in a nice neighborhood with a decent commute to your school is a necessity. You can take your time to ease back into school if you feel the need to do so. It might be best that way.
1c) Becoming a "parent" is a serious thing and it sounds like you will be the legal guardian of this child. That's okay. If that's the case it means your parents really trusted you and believed they raised you right. It's a huge responsibility and I'm sorry you have to take it so young, but your parents minds are probably at ease just thinking about the fact that you're there.

2) Definitely sell the house if it's causing you that much pain.

3) Start learning to budget. You need to get in the habit of spending less than you "make" because it sounds that's exactly what your parents did.

4) Keep track of your money to whomever you let manage it. Like those three people suggested that could keep an eye out for each other. Never stop asking questions about it. Learn what you can.

5) I wouldn't share with your friends in all honesty. Especially not just yet. You definitely need a support group. A support group does not need to know your financial situation to be there for you and give their support when you're grieving. Give yourself time to get used to not spending much with this money at all. Don't treat anybody out until you make your own from a job and then you can decide whether you want to do that.

Last thing. I'm truly sorry for your loss, but I just want to say you're doing a good job. In one week you've been through all this now you're trying to keep moving forward and building your life from all these pieces. You've shown tremendous responsibility in your post. You told us the situation, you're scared of what you might do, you're asking for advice, and you've gotten counseling for both you and your little brother. Your little brother is very fortunate to have you in his life. Your parents would be very proud of you.