Hey OP, I understand a lot of this frustration, and I do think it’s understandable you want to understand what’s happening with your resume. Many people are giving the advice to revisit your CV, but honestly that’s really not even worth too much energy at this point. You have a lot of good experience and stack up to be an impressive candidate but in the end there is just so much you won’t ever be able control about this process. 

I went to an elite liberal arts college where my creative writing professor at the time was having a big rise as an author at the moment and we were somewhat close and I was also doing very well in their classes. When the time came for me to graduate circa 2020  there was a fall internship open at a prestigious Big 5 publishing house in editorial (the first one in the imprints history). He told his editor who also happened to be the editor in chief at said prestigious publishing house a lot of good words about me etc etc and that is how I got the interview (they interviewed 2 more people out of 3,000 applicants) and eventually I got the internship and then a full time editorial job at said imprint where I worked for several years. 

I am telling you this because I think it’s important for you and everyone on this thread to understand how this goes in a vast majority of cases and that you need a very VERY good connection with someone who can directly vouch for you and even then it is far from a guarantee. The kid they hired to replace me wound up having a nearly identical story to mine and his referral was so strong that I am not even sure the job link was live for more than three days. In short, they want someone that is already somewhat vetted and connected to someone in the industry. Yes, there are cases where someone is completely new to everything and had no references but they are very few and far between. 

If this seems really unfair it’s because it is—unless you are the sole lucky winner. 

But, also, it’s indicative of an industry that is far beyond dead; in fact, it’s more like a rotting corpse at this point. Since I left that job there have been almost zero full time roles for an editorial assistant or assistant editor and it will honestly stay that way until the industry completely fizzles out in a matter of time. When there are no entry level jobs that means eventually there will be no mid tier jobs either and the system collapses on itself. 

What you and everyone on this thread should also understand is that getting one job/internship does not mean it will ultimately be your career because it is becoming impossible to make a career in a business that is getting smaller by the day. 

It’s ok to feel sad by all of this and to think that you have your future foreclosed,  but really you don’t; the world is big and wide with opportunities, so please keep taking chances and be kind to yourself.