Yeah apathy is the worst, I used to think it was depression but I even miss that now and have missed it for years because back then I could at least feel something and feel excitement and joy (not happiness) doing stuff I liked like playing video games or being excited about doing stuff with friends e.g in my stoner years driving over to a friend to have a fun night of smoking weed with all my friends.
So imo it doesn´t get worse than apathy not being able to feel or enjoy anything not even things like video games, movies, food etc. not feeling anything is worse than feeling everything because at least then you feel alive and with depression like I mentioned although it is truly horrible there is no denying that you can still be able to enjoy some things where with apathy and anhedonia you just "feel" empty there is nothing, no motivation to do stuff (lack of excitement apathy) and you don´t feel any fun or euphoria doing stuff you used to like (no reward anhedonia)