I hate texting my girlfriend
Why do you hate texting your girlfriend?
I feel that texting is not a formal way of communication, it should be used for arranging meetings only.
It's fine if texting isn't the way that you prefer to communicate with your girlfriend. If you don't want to text, you shouldn't do it. You should let your girlfriend know why it bothers you.
Maybe I should ignore her when she texts me.
I don't think you should do that. Like I said, it's much better to just let the other person know. She won't take it too hard.