my imesssage IOS 9.3.1 is not letting me text other people but i can see what other people text me

My IMessages on my IPod Touch IOS 9.3.1 says whenever i send a text that it sent but yet the other person never got my text, but i can see their texts that they send to me. I need to know how to fix this problem please. I have already tried rebooting, toggling IMessages button, signing out of IMessages then back in, and resetting network settings, but nothing seems to work so far. 😕