John the Apostle wrote saying, "that which we have seen and heard we declare to you, that you also may have fellowship with us; and truly our fellowship is with the Father and with His Son Jesus Christ".
1 John 1:3
"For there is only ONE God, and only ONE mediator between God and men, the man Christ Jesus;"
(1 Timothy 2:5).
And there is no other God but one and even if there are so-called gods, whether in heaven or on earth (as there are many gods and many lords), yet for us there is only ONE God, the Father, of whom are all things, and we in Him; and only ONE Lord Jesus Christ, through whom are all things, and through whom we live.
(1corinthians 8:5-6).
Therefore, God the Father is the Person of the Holy Spirit in Christ Jesus; that is, that God was in Christ reconciling the world to Himself (2Cor 5:19).
And Our Lord Jesus Christ is the Person of the Holy Spirit in all the saints, because through Him we have access by one Spirit unto the Father
(Ephesians 2:18).
As it is written, “The first man Adam became a living being.” The last Adam Christ became a life-giving spirit.
1 Corinthians 15:45
Therefore, Christ is the Holy Spirit and the giver of everlasting life.
And because you are sons, God has sent forth the Spirit of His only begotten Son into your hearts, crying out, “Abba, Father!”
(Galatians 4:6).
The Holy Spirit is crying out, “Abba, Father!” Because He is the Son of God and He is Our Lord Jesus Christ.
And this is Him who cried in prayer to God saying, “Abba, Father!, all things are possible for You. Take this cup away from Me; nevertheless, not what I will, but what You will.”
(Mark 14:36)
If the Holy Ghost is another person as you supposed, then he cannot cry out “Abba, Father!

How do you explain John 14:26
26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
And John 16:7,13,14
7 Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come unto you; but if I depart, I will send him unto you
13 Howbeit when he, the Spirit of truth, is come, he will guide you into all truth... and he will shew you things to come. 14 He shall glorify me: for he shall receive of mine, and shall shew it unto you.

When Jesus Christ said, I come in my Father's name. He was saying that God is in Him. Even so, the Holy Spirit is a Spirit and not a person, but the Name of Christ in the Holy Spirit makes Him a person.

When Jesus Christ said, I come in my Father's name. He was saying that God is in Him. Even so, the Holy Spirit is a Spirit and not a person, but the Name of Christ in the Holy Spirit makes Him a person.

It is easy to show and believe God is two persons from scripture, for me anyway

but it is a difficult thing to explain God being three persons.
In my mind it is clear, but putting it in writing is a difficult thing.