壊してしまいそうで怖いって英語でなんて言うの？

"I don't want to break it" This is a phrase used when you would not like to 'break'/destroy something, often not on purpose. to 'break' something is a term used to describe something that might get destroyed,smashed etc.. that it might become unusable. "I'm scared it might break" To be 'scared' of something, this relates to something that frightens you, something that you might be worried about.

I'm afraid it's stuck and I might break it if I push/pull too hard. It's stuck. It might break if I push or pull on it. I don't want to break it by forcing it open. It won't open and I don't want to break it. I think it's stuck and it will break if I try to force it. If I pull on it then it might break. It's going to break if I push or pull too hard.

I am afraid I might break it if I push/ pull too hard. I'm afraid I might break it. I'm not going to pull it as I'm afraid I'll break it. If I push it too hard then it might break.

"I am nervous about breaking the window/ door/ etc." If you don't want to take the risk of doing something you can say you are nervous. Nervous means to feel hesitant and scared about something.

It often happens that while one is trying to handle something like a door, a window or an appliance, the item breaks. This sort of thing can be very disappointing. So, usually, if a door, a window, or an appliance is proving difficult to open, most people will try and be as 'careful', or, as 'gentle' as possible when doing so to avoid breaking the item, thereby increasing the household's expenses unexpectedly. The trick is to 'exert' as little force as possible on the item to avoid breaking it. The verb to 'exert' in this context means to 'apply' a force onto something, in this case, a door, a window, or an appliance. So, you may say to someone: I am being extra careful while trying to open this stiff window because I fear that it might break. or This door is quite stiff and I am trying to be as gentle as possible while opening it for fear that it might break. or I am exerting as little force as possible on this very stiff window in order to open it because I am afraid it might easily break.

Afraid: scared, fearful, unsettled Breaking things is something we don't like, we do our best to avoid breaking anything around the house. just in case: making provision/ room for mistakes or making provision to avoid mistakes.

When trying to open a stiff door/window/etc. you want to say that I'm afraid that I might break it if I pull it too hard. Either of the above suggestions should be adequate.