First, say some or all of the prayers on the Rosa Mystica page here.
Then say this prayer, which you may adapt as you wish.
Most Holy Trinity,
Father, Son, and Holy Spirit,
in your mercy and love for me,
through Jesus, my Lord and Savior,
through the intercession of Mary, Joseph,
and all the Saints, Angels, and faithful souls,
have mercy on me, despite my unworthiness.
I beg you to forgive my sins and the punishment due;
I beg you to heal my wounds in soul, spirit, and body,
so that, forgiven and healed by the infinite Mercy of God,
I may be able, to the fullest extent,
to fulfill my unique role in the plan of God,
for the Church, my family, and the suffering souls of this life.
(And may God have mercy on you through my prayers and sufferings as well.)