[Question] What is the best or safest (non-viral) way to convert all of the music from my iPhone 6s to my iTunes library, since it is not possible to do through the iTunes software normally?

I bought a new PC and I want all of the music from my iPhone to be on my computer, not the other way around. My iPhone has music that has been taken from CDs, and it will be taken away if I sync my phone to my computer, since syncing from a computer takes all of the music in the computer's library and puts it on the iPhone, rather than the other way around.

It really bothers me that this is the case, but I've heard that there are nice programs that will convert the music in the opposite manner. I've looked at some, but I don't want to download anything without asking anyone about it first. The reason for this is because I recently got a virus on my computer and had to hard reset it and lose all my files. I'm looking for something safe, efficient, and simple.

Thank you!