What do you do if you are not sure if the presence are fallen angels, restless souls or both?

Here’s my advice: Do both prayers. Pray the one for fallen angels first, then the one for restless souls. If you are scared or the presence is very powerful and menacing, please call for a priest. I recommend calling for a Benedictine priest if you can find one.

Where to get holy water? Go to a Catholic church and ask for some. Bring a small container with you. Holy water is FREE.

"CCC 2121 - Simony is defined as the buying or selling of spiritual things. 53 To Simon the magician, who wanted to buy the spiritual power he saw at work in the apostles, St. Peter responded: "Your silver perish with you, because you thought you could obtain God's gift with money!" 54 Peter thus held to the words of Jesus: "You received without pay, give without pay." 55 It is impossible to appropriate to oneself spiritual goods and behave toward them as their owner or master, for they have their source in God. One can receive them only from him, without payment.”

New Advent - It is thus unlawful to exchange ecclesiastical benefices by private authority, to accept any payment whatever for holy oils, to sell blessed rosaries or crucifixes. Such objects lose, if sold, all the indulgences previously attached to them (S. Cong. Of Indulg., 12 July, 1847)".²

When to use holy water? Holy water has been my saving grace throughout this journey. Don’t just bless your surroundings --- bless yourself as well. I add some to my final rinse when bathing, I add a little to my drinking water. I highly recommend that you bless yourself and others with holy water after you go to a wake or burial, the hospital or the sick, and anytime you are emotionally down or physically unwell. Bless your homes frequently, your office, your car and every time you sleep out. Carry a small container of holy water with you always.

To appreciate holy water is to know the blessing that is asked when it is made. Holy water consists of salt and water.

The blessing on the salt:

Almighty everlasting God, we humbly appeal to your mercy and goodness to graciously bless + this creature, salt, which you have given for mankind's use. May all who use it find in it a remedy for body and mind. And may everything that it touches or sprinkles be freed from uncleanness and any influence of the evil spirit; through Christ our Lord.

The blessing on the water:

O God, who for man's welfare established the most wonderful mysteries in the substance of water, hearken to our prayer, and pour forth your blessing + on this element now being prepared with various purifying rites. May this creature of yours, when used in your mysteries and endowed with your grace, serve to cast out demons and to banish disease. May everything that this water sprinkles in the homes and gatherings of the faithful be delivered from all that is unclean and hurtful; let no breath of contagion hover there, no taint of corruption; let all the wiles of the lurking enemy come to nothing. By the sprinkling of this water may everything opposed to the safety and peace of the occupants of these homes be banished, so that in calling on your holy name they may know the well-being they desire, and be protected from every peril; through Christ our Lord.

The blessing on the mixture of salt and water:

God, source of irresistible might and king of an invincible realm, the ever-glorious conqueror; who restrain the force of the adversary, silencing the uproar of his rage, and valiantly subduing his wickedness; in awe and humility we beg you, Lord, to regard with favor this creature thing of salt and water, to let the light of your kindness shine upon it, and to hallow it with the dew of your mercy; so that wherever it is sprinkled and your holy name is invoked, every assault of the unclean spirit may be baffled, and all dread of the serpent's venom be cast out. To us who entreat your mercy grant that the Holy Spirit may be with us wherever we may be; through Christ our Lord.³