First of all, I’d like to encourage you in your desire to pray on a daily basis. Daily prayer is an important way of maintaining and fostering a relationship with God. You mentioned that your daily prayer consists of sitting in a chair and reciting a bible verse or prayer as a mantra. There are many different ways of praying, and prayer that is Scripture-centered is always on target. Your own practice seems very much within the tradition of Christian prayer.
A “high” feeling or an erotic feeling or sensation may indeed occur in prayer. The fact that an erotic poem, “The Song of Songs”, is included in the bible shows that our relationship with God can include erotic feelings. The experiences of Catholic mystics like St. Teresa of Avila and St. John of the Cross have often been expressed in highly erotic language. When we make the sign of the cross over head, heart and shoulders, we remind ourselves that we worship God not only with our mind but with our whole being, body and spirit.
“High” feelings are not the purpose or end of prayer, which is to grow closer to God and open our hearts to do God’s will. When we receive a feeling in prayer it’s best to acknowledge it and then let it go.Struggling to resist feelings, or dwelling on them and attempting to hold onto them, focuses attention on the feelings rather than on God. It’s advisable simply to let the feelings or sensations be what they are and then return the focus of your attention to God. The test of authentic prayer is not whatever feelings we have during prayer but whether our practice leads us toward a life in which our love of God is expressed in compassion and charity toward others.
I hope this helps to answer your question,
God bless you,