Hearing God?

I have been talking to God trying to get answers to prayers or just questions or concerns that I have and I feel like he's not answering me or that I am unable to hear his voice because of all that is going on in my mind. Sometimes I hear things but I am not sure if It is God, me answering my own question or maybe the enemy. How do I know if it's God?? I feel frustated after praying so much and not hearing anything. Thanks for your answers.