the worst thing you can do is read anything into it mate there are two possible things that have happened
1- she just decided she doesnt want to text you any more, in which case its her loss (as we all know)
2-Something is stopping her texting you back i.e. she has no credit, she lost her phone, her phone broke, etc
in either case there is nothing you can do about it without actualli seeing her... if its #1 and you still want her, u need to see her in person and attract her if its #2 then u dont wana fuck it up by texting her lots and coming off as needy (like you said)
Possibly just send her a text along the lines of "Hey, I assume something is up with your phone. When you get it fixed send me a text and tell me where and when you wana meet
i'll see if i can fit you in"Hopefully if it is the first reason, she will see that you are not bothered that she isnt texting back (hopefully making her want you) and if its the second reason, you will come off as a reali cool person who isnt gonna flip out worrying everytime she doesnt text you straight back......
this is a win-win situation..... your gonna look good lol