Would a girl stop talking to me just because of what I said in a text message?

Yea, sometimes girl tend to not like guys when they don't talk proper English. Why that is I'm not 100% sure. That could lead to a deal break with a girl you might be trying to get with. If she's just a friend, then it shouldn't be a problem. I talk to my female friends in slang sometimes too, and they text write back the same way. It honestly depends. If you guys are just friends i'm thinking that it'll work out. She's probably just busy. You may also want to try getting a hold of her, and just being like, "Hey I haven't heard from you in a while. Everything alright?" Just to see where it goes. You never know she might tell you whats up.