Dear friend
Any prayer said in your own words from your heart, the simplest movement of the heart deep in love with the Lord, raised and swept up in love with, to and from Him, blows away any Rosary ever said.
Any part of the Rosary said therefore, with that love in your heart, even if it is half a decade or a full decade is a Rosary that is above any Rosary said out of repetition, false sense of duty or dullness on the lips.
The Rosary is the ‘poor man’s’ meditation, it is not contemplation.
The Rosary is a prayer said with our Blessed Virgin Mother Mary throughout the life of Our Lord Jesus Christ (Our Blessed Virgin Mother Mary meditated on our Lord throughout her life, pondering all things in her heart, though she was gifted with contemplation as the Mother of God so she should be! She will aid your mediation on our Lord in this prayer of the Most Holy Rosary) bringing in this a deeper meditation on the Truine God and our Co-Mediatrix Mary.
You need only slowly pray one Hail Mary of that decade and mediate for half an hour on our Lord within that one Hail Mary to have offered the most Holiest and complete of prayers.
You are worrying about quality of prayer, when friend, the Holy Spirit prays, not you, you offer your prayer because the Holy Spirit aids you to do so, no prayer can be offered without Him.
At the beginning of any part of the Rosary you begin to say, start by saying a prayer to the Holy Spirit.
The Rosary is not about completing all of what is given possible to complete, surely that would only lead to spiritual pride to be a ‘completer’! The Rosary is about immersing yourself prayerfully in our Lord led there by our Blessed Virgin Mother Mary and any soul that is led to our Lord by His Mother is kept with Him forever.
Her Rosary is Her gift to you so that she may pray with you in deep meditation to aid souls and your soul. She will not neglect even a soul that has only prayed it once in their life. She will honour the soul that prays with all ernest even the smallest portion of her Blessed Rosary.
Worry is not the state of a Christian, worry is not something we are concerned with, we live in the Lord and we have nothing to fear or worry .
God Bless you and much love and peace to you
Teresa