I'd translate the word 'estufa' as 'an oven'.

'My bedroom is like an oven.'

And the expression 'passar calor' would probably mean 'put up with the heat'.

'I will put up with the heat.'

I'm not fluent in Portuguese but I think it'd all make sense in the context.

Hot, very hot

Last night it was almost impossible to sleep!
Because it was very, but very hot!

My bedroom looks like an "estufa". And even if you have a good fan, it's still not enough.

I need a good air conditioning conditioner, but at the moment I don't have money.
So, I will continue "passar calor".

It would be good to find a translation for the words you don't know in English!