If she's having a hard time, a text saying "why are you ignoring me" will not go down well, at best it will be ignored!
How about a phonecall, a positive one, one that says "I miss you, lets meet up" one that may make her think she missing something too.
I mean that nicely. When I was having a shit time I needed friends to be forgiving, I needed cheering up, although it's not 'nice' I didn't have time for more shit on my shoulders... just a cheery face, a few giggles a cup of coffee.
I have one friend who's life is far far more cause for complaint than mine, but she never complains (unless I really turn the screws on her) and wants the same as me - a mate to chuckle with. Because she is like this, we've lasted, and because she TRIES to always be positive, I always listen when she isn't. I think that's the crux of it, if you're not seeing each other often, make it happy and fun, something to look forward to. Over time, you will be able to offload your woes (I have been able with my friend) but if from your friend's PoV all she's getting is woe, why are you ignoring me? She's not going to look forward to seeing you.
On the other hand, maybe you've outgrown each other, or more sadly for you, she's moved on from you? It could be salvaged, it could be the natural kind person's break up... if it's the latter, you will hurt, but you HAVE to move forwards. What else can you do?
YANBU to feel it's like breaking up with someone, love is involved, just because it's not sexual doesn't mean it isn't love, and heartbreak is normal. x