Unsensical
describes something that doesn't mean anything.
I can't even say unsensical words that fast, let alone full, meaningful sentences.
Unsensable
Senseless, doesn't make sense.
You don't go backwards, stop being Unsensable
Unsense
A concept or statement that makes sense and is completely understood by the person/people perceiving it, but does not hold any external logical validity.
Averyham: if I were you I wouldn’t be me being you because when I become you I become 100% not me
Mankennedy: That’s makes no sense, but somehow I understand it
Averyham: It makes unsense!
Mankennedy: That’s makes no sense, but somehow I understand it
Averyham: It makes unsense!