You should think of using a language as like using a bicycle. It is not some deeply integrated part of your essence. It is not somehow what consciousness is made of ‒ there is no bicycle-riding soul. Using a bicycle is just a form of activity, and so is language.
The idea that some feelings are unsayable can seem to have a fascination, a mystery. But that is as misguided as wondering if some feelings are inexpressible by riding a bicycle. What does one express by riding a bicycle? Nothing really: that is not what bicycling is about: it is about going from A to B, or racing, or exercise, or things like that. Language is the same: it is about doing linguistic things. Words are not feelings, or made of, or extensions of them, any more than bicycling is.
‘Are some things unsayable?’ ‒ that is just a paradoxical formulation; like a game that is unplayable, or a word that is unwritable. If it is unwritable, it is not a word; if it is a word, it is writable. The idea that there is a something mysterious here that is both one thing and the other is confused.
Anything you do, any thing happening in your body, is describable – so what is unsayable? What can you do, what can happen to you, that is unsayable? This seems to point back to the perplexingness of consciousness sneaking in and confusing us. Yes, consciousness is subjective experience – but why make a problem elsewhere from that? What does that have to do with the plain and obvious act of describing things?
Look at this as agent interaction: there are certain ways we can be similar to others, and act in coordinated ways with others, and there are ways that are different, individual. We can categorise activities into those two. Something ‘unsayable’ is just something that is an individual action, not a common shared public action. Common actions all have some measure of individuality, but we cannot be both acting uniquely, entirely individually, and acting in a common pattern – and there is no problem, no mystical feeling about that.
An untranslatable word is so only in the sense that a whole language is not really translatable.
You can never talk about one thing. Whenever you talk about one thing, you are really talking about a set of things, a larger abstraction that covers various similar things, including that one. There are no absolute descriptions of anything. A description picks out a thing, from a background of others, by means of the same language used for all descriptions. Every description appears specific, but is a very complex implicit form of comparison.
What about feelings? Are there absolute feelings? It seems that pain makes you act in particular way, it needs nothing else, it has a simple effect that is what it is. Could not a description work like that, and have a particular effect as some action?
If you say that we do not look at the cut on our hand to tell if we are in pain, you are not entirely correct. The pure sensation is immediate and self-sufficient, but what it is grouped as, and so interpreted as, must depend on other experience. And we always and must do such abstracting and grouping, otherwise we could not understand, and act coherently, and would have no pattern in our behaviour/existence ‒ every thing would be noise: isolated and unrelated to everything else.
And to act coherently with other people requires abstractions to be shared, and that requires material things to be shared, and grouped, somewhere upstream.
Descriptions are particular(-ish), but still relative. Feelings seem absolute because they are not so obviously parts of, but seem prior to, a system of language. A feeling seems to stand alone, but to use a word is to use the whole language.