You should read:
(1) I can't stand it anymore
(2) I can't put up with that / this anymore
(3) To carry on x To keep onI can't bear it anymore
.I can't take it anymore
.I can't endure it anymore
.I can't tolerate it anymore
I believe the expression I cant stand it anymore
implies that someone can't stand something which is annoying, whereas I can't bear it anymore
does not necessarily mean that. The second expression sounds more angry and agressive than the first one. It is something you just say in a moment of despair. It is just my opinion anyway!
Before present my answer to your second example "Quando eu achei que não ia aguentar mais, eu encontrei força(s)
", I'd like to make some notes about the Portuguese verb aguentar
. Even in our language, it has different connotations. Shall we take a look on them?
We often use the phrasal verb to put up with (something / someone)
if we are talking about to tolerate something or someone unpleasant.
We had to put up with that situation
>> Tivemos que aguentar aquela situação
I don’t know how you put up with that neighbor
>> Não sei como você aguenta esse(a) vizinho(a)
If the sentence is negative or interrogative, the verbs to stand
or to bear
are preceeded by the modal verbs can
:I can't stand that girl
.I can't bear that girl
>> Não aguento essa garota.How can you stand the heat in here?How can you bear the heat in here?
>> Como você agüenta esse calor aqui adentro?I can't bear that pain
I can't stand that pain.
>> Eu não aguento essa dor.
If the sentence implies anything related to support something heavy
, we use the verb to take
The shelf won’t take that much weight
>> Esta prateleira não vai aguentar / suportar (com) tanto peso
In case of telling someone we can't control ourselves
, we say to be able to stand it
She couldn’t stand it
and began to cry.
>> Ela não aguentou
e começou a chorar.
The kid wasn't able to stand it
and began to yell.
>> A criança não foi capaz de suportar
e começou a gritar.
In case of talking about the experation date of something, we use the verb to last
This uniform will last a few more months
>> Esse uniforme aguenta mais uns meses
[To have physical strength to do something
] = To manage to do something
>> ter força física
para fazer algo = aguentar / suportar fazer algo
Can you manage to carry that box by yourself?
>> Você aguenta carregar essa caixa sozinha?
[To have inner strength to do something
] = To stand doing something
>> ter resistência psíquica para fazer algo = aguentar / suportar fazer algo
I can’t stand studying for the exams anymore.
>> Não aguento mais estudar para as provas.
1. to hold out
= [aguentar firme]
He held out and managed to finish the marathon.
>> Ele aguentou firme e conseguiu terminar a maratona.
2. To keep one's balance
= [aguentar-se] = equilibrar-se.
She was holding onto the rail to keep her balance.
>> Ela estava se segurando no parapeito / corrimão para não perder o equilíbrio.
Quando eu achei que não aguentaria mais, eu encontrei força(s) para continuar
>> When I thought I couldn't take it anymore, I found a way to go
>> When I thought I couldn't stand it anymore, I found the will to carry on
>> When I thought I couldn't bear it anymore, I found the inner strength to carry / keep on
(1) Pearson Education. Longman Dictionary. 2004.
(2) Collins Online Dictionary.
(3) I can't stand Trump because he treats people badly.