Is it possible to have two itunes accounts? Ive changed my apple id and music is missing?

I have changed my apple id to a different one due to so many mistakes on my part. Not knowing how to properly use an apple product...still learning and I believe some how my husbands email is synced with my apple id even though he has his owm id and password and so do i. I am missing songs in itunes and cant download them to the ipod i have. it's an older model I believe 3rd generation. But most importantly it seems like every time I send him an email to his icloud address...it comes to me. I need help in finding out how to correct this with out losing everything again. Any suggestions from only those without sarcasm. Some of the responses have been rude and not helpful. I just need help. I love my Mac book pro.