Being objective about your own song is impossible
Something I say a lot, usually to somebody who doesn't want to hear it: everyone thinks they're closer to the middle than they are.
Every great singer I've worked with thinks they're worse than they are. Every singer who isn't there yet thinks they're better than they are. Almost nobody lands on an accurate read of their own work, and the few who do got there by having other people tell them for years.
Same goes for a song.
By the time you're asking whether your mix is done, you've heard it two hundred times. You've heard it in pieces. You've heard it with one part soloed. You've heard Tuesday's version that had a problem you already fixed, and some part of your brain is still hearing that problem. You know where the second verse is going before it goes there, which means it can't surprise you, which means you can't hear it the way a stranger will.
You're not being precious. You are physically no longer the right person to evaluate this.
There are checks that partly work, and I'd much rather you run them than nothing:
The phone test.
Play it out loud on your phone at arm's length. Everything inessential disappears and you're left with what actually carries — the vocal, the kick, and whether the song has an idea. Brutal, and free.
The next-morning test.
Don't touch it for a day. Not four hours. A day. Then play it once, all the way through, and don't stop it. Whatever you noticed in that single pass is real. Everything you'd have caught on pass three is you tinkering.
The other-person test.
Play it for someone while they're doing something else, and watch them instead of the speakers. You'll know inside twenty seconds. People's faces don't lie nearly as well as their words do.
Those help. What they don't do is replace an outside ear, because all three of them are still being run by you.
Honestly, that's most of why I do this job. Not because I have better speakers, though I do. Because I've never heard your song before, and I only get that once. The first listen is worth more than the next fifty, and you already spent yours.
So spend someone else's on it.
Eight questions, two minutes, and an honest read on where your track sits. No call, no pitch. → Take the Skip Test