No. I pray to God every day, go to Mass often, ask for help from Mary and the Saints, and put all my trust in Jesus. God and Mary protect their faithful children. I don’t need to be afraid of beasts or marks or the Devil or any of that.
Please speak to a priest ASAP if you are continuing to be bothered by these thoughts. I quote the end part of St. Faustina’s Divine Mercy Prayer:
“And we expect to receive everything promised us by Jesus in spite of all our wretchedness, for Jesus is our hope; Through His merciful heart, as through an open gate, we pass through to Heaven.”
Or, as Joan of Arc said, “Be a good child, and God will help you.”