Your priest is right. As far as can be determined, Barnabas Nwoye is not a charlatan. His prayer book has even got an Imprimatur by Bishop Ayo-Maria Atoyebi of the Diocese of Ilorin, Nigeria. As of his visions, they are being legitimately investigated by the proper ecclesiastical authorities:
Episcopal Remarks: The messages of 1997 – 2000 have received the Nihil Obstat of Rev. Fr. Stephen Obiukwu, Chairman of the Propagation of the Faith, Archdiocese of Onitsha. Rev. Dr. Ayo Maria O.P., Bishop of Ilorin diocese, Kwara State acts as a spiritual advisor to the devotion and to Barnabas Nwoye. An Imprimatur was granted by Dr. Ayo Maria to the prayers and promises dictated on June 17th 2001. 1 A Theological Commission was set up by Bishop Anthony Gbuji of Enugu State, to vet the revelations. Four priests, four nuns and two lay faithful composed the commission. Although few members of the committee expressed some reservations on what Jesus had allegedly said about the current practices of the Church, they concluded that the messages largely agree with Catholic doctrine. A verdict on supernaturality is still awaited.
More on him here: Precious blood devotion.
The next thing you ought to do is to avoid Catholic Planet or depending on its accuracy of Catholic Doctrine. The site is highly questionable in terms of its faithfulness to the Magisterium. The owner claims to be a theologian, but his credentials are also highly suspect.
See here: Review of Catholic Planet.
This site is the venue for the writings of Ronald Conte, self-described as a Catholic theologian. His site features numerous articles about Catholicism. Most controversial are his eschatology writings which give precise dates of future events right up to the coming of Christ (which he predicts to be in the 26th century). His claims are based on his interpretation of the Bible and private revelation throughout history. While you may find something worthwhile on this site, it is replete with Mr. Conte's speculative theology. We suggest you avoid it unless you are a theologian and qualified to sift through and determine what is true and what isn't.