This may be a bit rambling as I try to sort the thoughts out, but bear with me.
As far as the scholarship goes, I wouldn't feel too bad about taking it, after all, the purpose of most of those scholarships is to provide talented enthusiastic people with the opportunity to study further and then be able to take that knowledge and apply it for the benefit of society, thus creating more value than the money that the scholarship was worth.
If you accept the scholarship and still feel bad, then when you are rich and famous from your prowess in your given field, you can give back by establishing a scholarship fund of your own to help other people out who also may not have got the opportunity otherwise.
The other benefit of grad school is that it will give you a piece of paper. Now while this piece of paper won't make all that much difference to your life/career 5 years after you get it, it will open doors for you that not having it would ensure remained shut.
The job sounds like it may not be right for you, but you need to look critically at whether not having the job and as a result, having no source of income would be worse than trading some of your time at a repetitive job for a "secure" income. It may be possible for you to start freelancing with your art even while studying and taking the pictures, and if you get well known enough at the freelancing, you should ultimately be able to quit the repetitive job. One of the sites to check out is
Get a Freelancer There are more out there like this one, but this is the only one I know of the top of my head. Also, and I don't know what type of art you do, there is the opportunity to licence artworks/illustrations through microstock agencies in the same way you can with photographs. 123RF, Dreamstime, fotolia are just a few sites you may want to check out.
Unfortuneately, I have no advice whatsoever on the family situation. I tend to avoid my family because they drive me crazy, and while I'm used to just ignoring their annoying habits, when they turn their judgemental, narrowminded, opinionated views toward my wife, I get angry, leave and don't speak to them for months.