I was studying 禁じ得ない that apparently means " cannot control, refrain a sentiment". It really feels similar to form such as たまらない、仕方がない、やまない and ずにいられない, but I don't think it's the case. Can somebody clarify it to me?
[noun]を禁じ得ない "cannot hold back"
This construction can only take nouns that mean emotions (驚き, 喜び, 笑い, 涙...). You must find a noun form even if you want to say something in a verb or adjective. It is an expression so literary that only becomes a joke when you use it in conversation.
[verb](nai-stem)-ずに（は）いられない "cannot help but"
Same as above except it only takes verbs and not limited to emotions.
[verb](masu-stem)-たくてたまらない "be dying to"
[i-adjective]-くてたまらない "unbearably; irresistibly"
[na-adjective]-でたまらない "unbearably; irresistibly"
Basically it takes adjectives to mean the extreme degree of feelings. You can also make use of verb via たい "want to" in the middle, but note that it does not imply that you actually did it, unlike the two above.
[verb](te-form)-仕方がない "annoyingly keep —ing")
Interchangeable with the previous one. There is also the last usage which is not really the same formula, but maybe confusable.
Literally it means "stop at nothing", but like "eternally grateful" in English, it is rather used to say that the feelings never change i.e. in earnest. It is often collocated with 求めて "crave", 願って "wish", or 愛して "love" etc.