I am so pathetic about my ex, help please!?

Be polite and cordial to her. She was just asking for a number..I really don't think her not replying means anything. If she texts you back dont ignore; thats really immature. The best thing you can do is just live your life and try to have fun. I know it seems impossible but you will get through it. Remember everyone goes through a breakup with someone they loved. Just keep your head up and try to occupy yourself with other things. If she is constantly texting you and you feel like you wont be able to get over her if she keeps doing this than nicely tell her you can't communicate with her until you have healed a little more. I'm sorry its hard I know.