I've had varying success but I think the problem is that my beats probably isn't the best, and I want to ask what's the FASTEST way to get better aside from listening other producers that have better beats.
Bro, share your beats for us here! Let us listen :)
Also ask yourself, if you would be an artist - would you rap/sing on top of your beats? would they inspire you creatively? If the answer is YES - then all fine, but maybe you need to level up some quality in them, or maybe you don't need to invent the wheel again.