Ok make some kind of commitment on what you think it does say. You know it means he would be a "cohen" (priest) similar to Malki-tzedek.
I can present exactly what it says
נִשְׁבַּ֤ע יְהֹוָ֨ה
׀ וְלֹ֥א יִנָּחֵ֗ם אַתָּֽה־כֹהֵ֥ן לְעוֹלָ֑ם עַל־דִּ֝בְרָתִ֗י מַלְכִּי־צֶֽדֶק
why don't you go through that and explain, word by word, how you get to the translation you keep relying on. Show me "Like" or "similar" in there. Show me the future tense. They aren't there and your blind insistence doesn't change that.
Here is one way I can translate it:
God swears, and he won't go back on his statement, "you are a chief forever, on the basis that I spoke of regarding Malki-tzedek."
Of course, I could just quote some translations from others
"The LORD has sworn and will not relent,
“You are a priest forever, a rightful king by My decree.”
There is also this one
"The Lord swore and will not repent; you are a priest forever because of the speech of Malchizedek."
But you don't like these because they don't conform to the inventions you need in terms of the words.