How to Recover Lost iTunes Library after Hard Drive Crash

I had used my old computer for seven years and a few days ago it got Hard Drive crash accidentally. I couldn’t express how annoying and painful due to this case because I had my irreplaceable songs imported from CDs and download from the Internet in my iTunes Library lost.

The only one thing I was grateful was that some music was stored in my iPhone 6. Now I have to buy a new computer and install a totally new iTunes on my new computer. Is there any way to recover the iTunes Library with my iPhone? Any hope?