Music Starts but will instantly stop again. Frequently just starts the song over again.

Every time I click the play button with my spacebar, the music seems to just play the first note given and just stop. If I would press spacebar again after it stops, it starts playing the song from the beginning. Happens about 80% of the time I hit spacebar. I tried sending the file from my desktop computer, to my MacBook Air, but when I open it up on my laptop, it works fine for about 20 minutes, and then it gets worse. I spent countless hours on this song and Im scared that the file might be corrupted or something. I would be happy to send this to support in private, but I would like to keep it private until I finish it.

Thank you :)