trying to figure out if nursing is for me.

I signed up for this website, because my grandmother is an RN, I'm really interested in starting a career in nursing. Here's the thing, I just turned 18, I want to have a career helping people, I'm scared to try nursing I really am. My grandmother and father were so excited when I told them how I was considering being a nurse, one; because I did so bad in high school I didn't even finish, my father thought I was going no where with my life, and he kept telling me I had wasted intelligence, because I am really smart, I just didn't have the motivation to finish high school. I've been living on my own and by myself since I turned 17, not a long time, but I've been working 2 full time jobs this whole time, 80 hrs. a week, and I've been doing it long enough to know I don't want to do this my whole life. I've always thought about being a social worker but I was told they were always laid off and made very little money. Once my grandmother started telling me about her nursing days, it got me so interested, because it has great pay and great benefits and she's experienced so much doing it, I want to do a career helping people. Especially kids.

Here's the thing:
I read a few posts from a few members on here, who said how they hated their job as nurses, and how they went into the career for the same reason I want to, (because they care), and they realized that nobody else gave a $hit. And I'm so scared to go into it because it's a lot of work, (that I'm willing to take on), but I'm scared I'll fail at it. I just want some reassurance (don't think I'm stupid if I spelt that wrong) that nursing IS the right career to go into, and that I won't be dissappointed when (and if) I finally succeed.

Please help me feel a little bit better.