You're NOT failing! Do not ever tell yourself you're a failure. That's an assholish thing to tell anyone; let alone yourself.
Whatever it is you feel you're failing at - whether it be losing body fat, gaining muscle, eating too much, not eating enough, etc. - you're not failing; you just haven't gotten your shit dialed in right now.
First, you have to decide not to fail. You have to decide you want to succeed. Then, you take the steps to take control of your shit. Like this:
I've been missing workouts. Don't fucking miss workouts.
I haven't been eating nearly enough protein. Eat more protein.
I keep forgetting to take my creatine. Knock that shit off.
I haven't tracked my calories in days/weeks/months. Track your fucking calories.
I don't know what my macros should be. Figure that shit out and hit those numbers.
See how simple it really is? It's all in your mind, beautiful people. Take control of the shit your CAN control. Do you know what a powerful feeling that is? DO YOU?!?! It's so much more enjoyable than feeling like a deuce about yourself because you're not progressing towards your goals.
The only one responsible for you reaching your goals is YOU. And YOU have total, absolute control to reach your goals. Why aren't you taking that control? What's holding you back???