Syncing Itunes Library

I have several songs that are unavailable on the apple store that I have purchased and downloaded through bandcamp. I have downloaded them and added them to my itunes library on my pc. both my phone and itunes on my PC are updated to the most recent version. when I plug in my iphone, it shows up and I can make a backup of it, but clicking on the music tab under it in itunes shows as follows in the image.

there is no dragging and dropping files, there is no sync button, there isn't even a full list of the songs that factually ARE on my iphone, and should show up here. the ones that do show up are greyed out. I have tried several things including changing my settings on my phone and resetting sync. I am appalled that what used to be an easy thing to do, is now impossible.

again, a subscription to apple music would not fix this, as the songs I want to move over, are not available through apple. The only way to get this music onto my phone, is by moving it manually.

I suspect this is a backhanded way to force people onto apple subscription; which again; wouldn't even solve my problem. I am nearly certain techs have been given a script to follow that avoids actually addressing this issue, based on what I have seen on these forums.

that said I am here because I am HOPING that the above statements are not true and that there is a simple solution to this issue. Please do not bother me with suggestions for basic things such as restarting devices or making sure that everything is at the most recent version; as stated before these things have already been tried and checked. let's move on to actual solutions.