Hi Marie,
It's great that you're seeking the truth, instead of just switching off like I did years ago! I believed in God as a child, then just stopped believing when I was seventeen. I was an atheist for 6 years, then God revealed Himself to me. I don't believe any person can convince you, or anyone else, of God's existence. God alone can do that. Keep asking, and He will convict you of the truth.
'And so I say to you: Ask and it will be given to you; seek and you will find; knock and the door will be opened. For everyone who asks receives; he who seeks, finds; and to him who knocks, the door will be opened' Luke 11:9