Will you help me calm my nerves?

First off, you need to take all your concerns to Jesus, on misconception people have is that since God is all knowing, you are not required to talk to Him about it. Jesus wants a relationship with us, so let Jesus know whats going on and as you pray go to the Bible and ask God to speak to you. Next, spiritual warfare is a tough thing. Satin enjoys messing with us. Jesus says that all authority in heaven and earth has been given to Him, and He gives us access to that power by the Holy Spirit, as long as it is within His will. So the next time you have that though rebuke satin. Tell him that you are God's daughter and that he has no power over you. Then I would suggest reading some offensive Psalms like, Ps 23, 27, 46, 63, 91, 100, 146, etc... Hope this helps, Blessings!