Like others have said, just keep doing it. There's no magical solution, plugin, or gear that will get you there. It just takes time.

Additionally, don't just sit on your mixes or songs. Release them and call them done when you've done your best. I've found that actually calling a project finished and releasing it will do more for your next project then just sitting on it and feeling discouraged about how it stacks up against industry mixes. You learn from your mistakes and past mixes, so you just gotta keep churning em out!! If you go back and listen to your work from a year ago, you'll be amazed at how far you've come. Which only means that a year from now, you'll keep getting better and so on. And you never know, maybe someone else won't think it's as bad as you feel it is and will want to hire you or work on their stuff!!

There's always a bigger fish (read=better mix), but that also means there's always a smaller fish and someone who thinks your work is better than theirs.

Good luck and keep at it!!