Have you been friends with this friend for very long?
Have you always given more to the relationship than she has?
How has your friend been there for you in the past?

It isn't unsual for friendships to fizzle away. Sometimes, long friendships can be put on the back burner for a little while and then brough back up to the front & the same closeness is still there. I have one terrific friendship that is that way ~ we have been friends for 30 years!

If, however, you're needs aren't being met, it's also possible that she isn't a true friend. I've been on that road too. Painful, yes. But it's better that you get out of the relationship before more damage is done, rather than continuing to follow her around & hope that she'll be there one these times.