You will not find the phrase Scripture alone in Scripture. But you will find passages and words that say Scripture is the source for all issues of faith, doctrine and practice either directly or through the priniciples found in Scripure.
Jesus said it best.
Matthew 4:4
But he answered and said, It is written,
Man shall
not live by bread alone, but
by every word that proceedeth out of the mouth of God.
With this, any "new revelation" must conform with the priniciples and teachings found in Scripture.
Let's focus on the first paragraph of what you said. A couple things--
1. Which "passages and words" do you refer to when you refer to "passages and words that say Scripture is the source for all issues of faith, doctrine and practice"?
2. What "Scripture" is referred to in these passages you have in mind? For instance, you might point to 2 Timothy 3:16, but when Paul wrote those words, "Scripture" would not have referred to what we now have as the New Testament - much of which wasn't even written by the early 60s (and all of which wasn't fully agreed upon informally until the late fourth century {and not formally settled fully until the 16th century}). Instead, Paul was referring to what we call the Old Testament; but even saying that, we have to caveat that it's not exactly clear what books Paul considered "Scripture" out of all the texts that were available at the time (since there was no formal, agreed-upon "canon" even of the Old Testament, outside of the Pentateuch, in either Jewish or Christian circles until after Paul's death - at best, it seems, we could argue that the Septuagint is what Paul had in mind here {since we know from his Old Testament quotations that he used the Greek translation of the passages he quotes, generally}, but if you concede that, then you'd have to accept the historic Christian canon {that is, the Catholic canon} including the Maccabees and the rest that Protestants have excised from their canon). If, as you implicitly seem to argue, these passages are authority for treating the existing Protestant Bible (and nothing more) as the relevant "Scripture" - well, by what or whose authority was *that* decided, since that's not the "Scripture" referred to in these passages of Scripture?
As for Matthew 4:4, you seem to acknowledge that it doesn't say anything about "sola" Scriptura. And to the extent you mean to imply that "every word that proceedeth out of the mouth of God" means the Protestant Bible - well, that presents all the same problems in point (2) above.
As for your third paragraph, Catholics wholeheartedly agree that dogma must "conform with" Scripture; so I don't think the point is relevant to the "sola" Scriptura question.
Finally, there are a number of passages in Scripture that underscore the equal authority of verbal instruction alongside written instruction. In 2 Thessalonians 2:15, for instance, Paul tells his audience to "hold fast to the traditions that you were taught by us, either by word of mouth or by our letter." In other words, Scripture itself speaks of non-Scriptural (indeed, non-written) matters as authoritative. In other words, to use your phrasing, Paul is pointing here to something other than "Scripture" (as you seem to use the term) and yet he clearly treats it as another source for "issues of faith, doctrine and practice." How do you reconcile that with your claim?