I have an old Apple ID How do I merge my music from my old account with my new account?

In college I had iTunes on my computer with both music from CDs that I uploaded to iTunes as well as music that I purchased. When that computer crashed, for some reason I guess I must have created a new Apple ID and account. Now I am trying to merge the accounts so I can access my older music. Ideally both the music I uploaded AND the songs I purchased on iTunes, but at the very least, gain access to my previously purchased iTunes songs. Can someone please assist? When i tried to request help from the Support Team, it seems that they only assist with hardware issues and this is not a hardware issue. Thanks!