Consciousness isn’t changing
Consciousness means the ability to pay attention

Awareness means having information about something

We are at all times aware of thousands & perhaps millions of things

When you are able to pay attention to something which you are aware of, you say you are conscious about it.

So with meditation, consciousness isn’t changing , it is enhancing.
Now you have an increased ability to pay attention to something you are aware of at will which earlier you weren’t, hence you were caught in those thought patterns.