Work and I have to sort out our differences

Nobody I know seems to get this, because I'm a stupid teenage girl who gets everything she wants and is selfish (atleast, thats what they're opinion seems to come off as).

I'm not very good when it comes to work. Its not that I'm slack, or that I'm lazy (although I am sometimes), its just that each time I wander into the working world, ready to DO something; somebody spits on me. Sometimes in my face, sometimes on my shoes....
No literally, although, I think that might be better. I'd rather be physically spat on than emotionally spat on.
I liked working for my mum, thats was good. And it was good because of the people who I worked with! They were good. I was a cleaner and a receptionist. I did ALL the messy, dirty, boring jobs that nobody else wanted or was bothered to do.
And I LIKED that job. That was fine.

Then I had a brief (very brief) stint working at my dads friends work. It would have been a brilliant opportunity, had I been ready for it. But it wasn't for me, you know? It just wasn't what I was looking for, I knew there was no point in me staying there because I didn't want to follow that as a career!
I got the major guilts put on me for ditching that one. I felt bad enough for wasting peoples time, I didn't need to know how disappointing it was.
That was a spit on the shoes. Something unpleasant, but not all that bad. Because I learned from it, that I wasn't interested in that area of work.

Then there was the cafe job... That was..... a big spit in the face - several times. I couldn't stand that place. The cafe work was okay, it was busy, but hey... talking to customers and cleaning, whats so bad about that? I just could NOT stand being around the people there.
Moods of the people around you influence your mood, so I was stressed, and miserable there. The people I worked with just constantly seemed angry.
It made me hate waking up in the morning, and going to bed at night knowing I was going to have to see them.

Now I got another job.... I was a little excited about it. I went through the interviewing motions... but then, the spitting part was when I got the surprise that it was ACTUALLY 37 hours a week! Not the 15 I was happy with. Not the 15 I applied for.
Cool, extra money. What the f? I haven't ever been a money driven person. I'm not ready for that - for THIS - because I started today. Once again, I go to bed thinking "Waking up will be shit...."

And yup, my family are thinking "harden up".
I knew they wouldn't bother trying to understand.