Read His Word the Bible. It contains so many passages that can help you. First of all know that you are forgiven John 3:16 and then go from there. Read the Psalms and meditate on them. God is always there for you.

He will keep you in perfect peace whose mind is stayed on Him. Fear is a liar and God does not gives us a spirit of fear but of a sound mind. Tell the old devil that you are a child of the King and a child of the King is so special to the King. He loves you so much and when you feel like you are anxious--put on the garment of praise for the spirit of heaviness. God's got your back!!!!!

Honey, My mom and dad both suffered with alzheimers. My prayers are with you, the best thing you can do is love them. When she says things you know are not true just smile and say God loves you. She thinks she is right and it is hard to convinced otherwise. Pray, pray pray and commit her to God and ask for wisdom to deal with the situation.