What If Your Girl Friend Is Not Showing Love To You Anymore?

Just walk away from her

Speak to her.
There are many reasons why people stop showing love, it could be simply that she's fallen out with her mum/dad/best friend, or dealing with something that's hard for her, and she thinks she must do it on her own.
It could be a sign that she needs more from those around her, I'm not saying that you should do more, but maybe mention that you're there for her if she needs to talk.
Tell her that you'd like to spend more time with her, and you enjoy the time you do have.
Maybe her confidence has taken a knock, or she's being annoyed by someone at school/work, or things are getting on top of her a little bit.
She could be worried about something.
There are far too many things and the only way to fix your relationship, and possibly make it stronger, is by talking to her.
Maybe take her for a nice walk, take her to the cinema, or a small gesture to open her up to you.
Sorry I can't help anymore than that, but I hope it helps you think of how to go about it.
She could simply be in a bad mood as it's 'that time' of the month.
I get moody and irritable and don't want anyone near me when it's mine! Sorry to overshare there but it's a possibility.
Take care

MrsE