Almost all of my 3000+ songs disappeared. Please help! I do pay for icloud. were do I access my itunes account online?

After the last iphone update, most of my itunes music is gone.

I had 3000+ songs and I am feeling like Apple music might have something to do with it.

I do pay for icloud. Where can I find my itunes account? not impressed!

Can anyone help?

Cheers,

Dorothy