It just doesn't prove sola scriptura to you. Apparently you need the Catholic Church. You need for them to tell you what is written in the Bible and what it means. This is exactly what your Church wants. Your dependence. There's nothing in the Bible to suggest we are to depend on any man made institution. Jesus, our Example, beat back the devil and his temptations with a "It is written". We are to do the same. He didn't say "My Church believes" or "My priest says" or "Our traditions say" but an "It is written". It was good enough for Him therefore it should be good enough for us.
Jesus never wrote anything, but He did build a Church. He gave it the keys to lose and bind on earth and in Heaven, and the authority to forgive sins, and promised it the Holy Spirit to lead it to all truth, and that the gates of hell would not prevail against it. Yes, scripture is the heart of the Church. But rip the heart out of the body in which Christ intended it to be nurtured and taught, and that heart will not accomplish what the Lord intended of it, as the 30,000 bickering and opposing sects prove.