I'm trying to parse the sentence below.
Book translation: I didn't know what to do because everyone was staring at me
Here's my reasoning:
The sentence is in indirect passive because the verb 見つめられて is the te-form of 見つめられる, which is the plain passive form of 見つめる as it wouldn't make sense to consider it to be in potential form, and, assuming 見つめられて inherited the intransitivity of the main verb, 困った, there's no direct object, so it cannot be a direct passive sentence.
The performer of the action, みんな, is marked by に and the understood subject, I, is omitted.
I don't think the translation is completely accurate, though. 困った is in plain past form and so is 見つめられて. Therefore, it should be translated as the following: I didn't know what to do because everyone stared at me. However, the meaning is basically the same.