Downloadable Product Not Downloading

Hi everyone,
I have downloadable mp3’s which are available from my website https://www.selfhypnosismp3downloads.com. I could not upload these through Media Library because they are too big (typically 25 – 35Mb each), so I formed a download folder for them on my server and I typed that path into the Download Path field on my Add New Product.
I just got an email from a customer saying he got an email from the site with his username and password but when he tried to login using the correct username and password, he can’t login and is being told his login details are incorrect. He emailed me the username and password and I have tried it myself and it doesn’t work. Because this doesn’t work, he cannot download the mp3 file that he has bought and paid for, so I need to sort this out pronto.
Any suggestions gratefully received
Any suggestions?
https://www.selfhypnosismp3downloads.com