1.
Not Very Nice
You're not mean, you just have to look out for yourself and you don't always have time to help others. Plus you work hard for what you have, others can work hard too.
It's not that you don't like to give, you just don't want to be taken advantage of. There's a good chance people weren't very giving to you in the past and you had to do many things on your own.
Remember that it's good to have people on your side who love and care for you and it's okay to be nice to them. Yes, sometimes you do need to set boundaries, but other times you can give a little bit extra, especially to those who you care about.