You might also consider wearing a miraculous medal. Mary is the queen of purity and pondering her life can be a huge help. As to the medal, wear it with faith, as it is a physical object, a sacramental which you can grasp as both reminder and reassurance that she is interceding on your behalf. Holding it firmly as you slowly and meaningfully offer a Hail Mary prayer might be just the ticket. It is no magic amulet - whatever you do must have faith as its foundation or it will be worthless, or even worse! You can ask father to bless the medal and bear that also in mind.
A small vial of holy water is another possibility. Demons hate holy water. They know when it is present. Crossing yourself with holy water is a sign, both to you and malevolent spirits that you are serious about repentance.
Since this is a battle in the spiritual realm, do not be surprised if a sudden wave of temptations arrive. This often occurs when we are drawing nearer to God while also rejecting the evil one. The charism of fortitude is worth asking for!