What it means
たまらない expresses an overwhelming feeling that is difficult or impossible to endure. It is used when the speaker feels something intensely, such as anxiety, bitterness, anger, longing, or another strong physical or emotional sensation. It commonly follows a verb in the て-form, an i-adjective in its くて-form, or a noun or na-adjective followed by で. The familiar form is たまらない, while the polite counterpart is たまりません.
Usage note
たまらない normally describes the speaker's own intense feeling or a feeling directly observed in the subject. With a third-person subject, it is often used with quotation, reported speech, or clear contextual evidence. It should not be confused with たまらなく, which means “extremely” and modifies another adjective or verb.
How to use it
故郷を訪れ、懐かしさでたまりません。
Visiting my hometown, I am overwhelmed with nostalgia.
一人で待っていると、不安でたまりません。
When I wait alone, I feel unbearably anxious.
この薬は苦くてたまりません。
This medicine is unbearably bitter.
約束を破られて、腹が立ってたまりません。
Because a promise was broken, I am unbearably angry.
故郷を訪れ、懐かしさでたまらない。
Visiting my hometown, I am overwhelmed with nostalgia.
一人で待っていると、不安でたまらない。
When I wait alone, I feel unbearably anxious.
この薬は苦くてたまらない。
This medicine is unbearably bitter.
約束を破られて、腹が立ってたまらない。
Because a promise was broken, I am unbearably angry.