Q: How to recover itunes libarary from timemachine

I recently DOWNgraded from Mavericks via sierra to yosemite.  Today I realized that the biggest part of my music is gone from my Iphone 5se.

After itunes now only imports a random collection of songs as albums, "recently added" is not working as only a small percentage of songs is showing I created, according to a advice i got here, smart folders with a date stamp as criteria.

Today I wanted to sync my phone and when it was completed 80% of my music was gone!

Also according to a threat here I deleted all songs from the phone and did a complete re-import, with the result that now all custom smart folders are gone from my itune library on my mac as well.

As there seems to be hundreds  of threads with this problem here, at macrumors and other sites it seems I'm not alone with this.
As I really can not bother to write codes, and reset half my computer, if I want to do that I can buy a microsoft machine, I just want to go back to yesterday when things where partially better.

However when I go to timemachine > apps>iTunes>restore it tells me that Itunes can't be deleted or modified because its part of the operating system.
To make a long story short, how do I get my songs back??