So, you're claiming that if a prophet gives a literal prophecy, every single other prophecy from that prophet has to also be literal? Likewise for a metaphorical prophecy?
(Isaiah 11:1-2)
1 A shoot will come up from the stump of Jesse;
from his roots a Branch will bear fruit.
2 The Spirit of the Lord will rest on him—
the Spirit of wisdom and of understanding,
the Spirit of counsel and of might,
the Spirit of the knowledge and fear of the Lord—
As we see above, verse 1 is metaphorical, as Christ Jesus was not literally a shoot from a literal stump from Jesse's literal roots (Jesse didn't literally have roots, and wasn't literally a stump), and Christ Jesus wasn't literally a branch that bore literal fruit.
But then in verse 2, everything is literal.
In the above, a literal [the coming Lord] is communicated via a metaphor.
Said literal is then conveyed directly, or literally, in the verses that follow.
Its metaphor aspect is even possible because said metaphor itself is comprised of imagery of the literal - imagery of literal stumps, roots, branches, fruit...
Then, the literal said metaphor is actually conveying through its imagery of a literal stump, root, branch, fruit is expanded on in the verses that follow.
Why the use of metaphor to begin with?
Because a picture being worth a thousand words, it is a useful as a means of conveying an understanding through said "picture" that is "easy to be understood."
Your problem is that, were you to be discussing some problem at work with a co-worker; should they respond with "you know how it is; you can't fight city hall," you'd fail to see said figure of speech for what it is, let alone that it was meant to convey, through the imagery of one, hopefully shared sense of a literal reality, another literal reality.
Your problem is that, where some might see the half-full as the half-full part of the whole; the other being the half-empty, all you and yours can see is either the half empty, or the half full.
Ours is Dispensational in that Dispensationalism is Distinctions - is both the half full and the half empty.
Yours is the one size fits all that ever blinds you from being able to see the one or the other half.
Not surprisingly, you will respond to this post from this very malady of yours.