How to get yourself in the mood to pleasure yourself?

Lately I've really wanted to masturbate and haven't been in the mood? Like I'm turned on and I want to, but I'm just nah. What can I do to make myself want to do it?

Also, where's my g-spot? I've recently tried penetration with a sharpie and I get wet enough, but I did't feel anything. Am I doing it wrong or am I not going far enough in? If I hit it, will I have a really intense orgasm?

And one last thing, how can I make my nipples erect and more sensitive to pleasure? 

Thanks in advanced!!

P.S I'm a girl!