First, examine your conscience and then GO TO CONFESSION!
The character conferred by the Sacrament of Confirmation can never be removed or lost, but it can lie dormant in you while you are in the state of mortal sin.
Go to confession, if need be, make a good Communion, and pray this prayer.
For private recitation.
“Almighty God my heavenly Father, You knew me before the creation of the cosmos and You wanted me to come into existence to bring You glory. Of all the possible universes You could have created, You created this one and You called me into it at exactly the time and place You chose for me so that I could fulfill my part in Your unfathomable plan. You willed that I have the honor to be baptized into the Church You designed and You maintain for our well-being. You willed that I receive the Body and Blood of Your Son and the indwelling of Your Spirit. You willed that I should also be confirmed so that our relationship be even deeper and that I might be an even better instrument of Your will. I now call upon that mighty Sacrament of Confirmation. Through it make me strong to bear whatever burdens I must endure in Your service. Make me wise to recognize accurately and then strong to resist, resolute, whatever is out of harmony with Your will as manifested especially in the beautiful Tradition You have guided in the authoritative, infallible and indefectible Church. Even if that disharmony should come from those whom you have endowed with the grace of Orders and seated even in the highest places of teaching, governing and sanctifying, make me steadfast. With confidence in Your plan for me I ask this for myself and for the brethren through the Holy Spirit’s Gifts and in the Name of Jesus Christ Your Son, who lives and reigns with You, ever one God, world without end. Amen.”