Here's my roundabout opinions of language/consciousness.

We aren't conscious, and we aren't the thing we hear speaking and thinking our whole lives. Instead, those things are us listening to activities elsewhere in the mind which tell us what is going on in whatever part of the head defines us.

In this case, language isn't necessary to have thoughts, and language is no more than an echo of thought. However, language is necessary to have a format in which our thoughts and be expressed, and easily listened to and reprocessed. We can reconfigure words to create new thoughts, or express our internal states.

Language is a mirror, in this case, and we start at it our whole lives and call it "me". In reality, if you have an efficient system you are going to have parts that aren't aware of themselves, and it is my assumption that whatever "we" are in our heads is one such part. We are made self aware by that which is not us.

Language, at least in the form of some ability to express the state of the mind as a simplified series of symbols, is necessary for "human-like" thought, in my opinion.