Exporting my animation from the middle cuts out the audio!!

I currently finished a 2 minute long animation with music in the background which I imported myself. I attempted to export it in Media Encoder, but its too big to export. So I split it into 2 parts, and I had to export the first half, and then export the second half separately. My issue is, the second half has no audio but the first half does. I think this is because the second half is starting in the middle of the audio. I don't know how to fix this, and any help would be fantastic as I'm on a deadline.

By the way, I'm exporting them from Media Encoder as MP4's, if that information helps.