great movie, but the soundtrack was driving me crazy

I agree. Just watched the movie and came to see if anyone had posted about this.
It's an excellent movie but the soundtrack really kills it in the moments where the focus should be on the character, you have these annoying screeching high leitmotifs that make you want to shut it down entirely.
I guess they were trying to simulate the pressure he felt when he wanted to drink but damn, it was really not working for me.

For every lie I unlearn I learn something new - Ani Difranco

I agree, that creepy Theremin, which is often used in horror movies was a little over the top.

I almost stopped watching because of it. So incessant and manipulative.

I thought so too, until I realized that it was portraying his desperation. Good movies need help to tell a story. Great movies use all senses. This story was told with pictures and sound. When he lost hope the music was loud to show how he was losing his battle. The music also helps us understand his desperation, some get it with just words, or pictures or scenery, but music can heighten the experience, allowing us to add our feelings to the story. It's like the director Hitchcock and the movie Psycho. He didn't want music for the shower scene but his team did and what a scene. It drive our imaginations to places we never want to be alone.

If we can save humanity, we become the caretakers of the world