Remember: "problem" is not necessarily bad. We just tend to see it that way.
You might be exercising to solve the problem of improving something that is already quite positive. Increasing already ample strength, building upon an already impressive physique, or maintaining an already consistent and healthy exercise habit.
Then again, you might be looking to use exercise to "fix" something about yourself. "Not good enough" is a rough point of view; and, an internal one.
That is a mistake. Making yourself wrong for the physical body you have right "now" is a distraction, it is self-flagellation and it is a total waste of time and energy.
It is also very human. So, take a moment to sit in it (if one is truly needed).
Instead, seeing your exercise as a potential means of solving a problem frames you as the hero of your own story.
That usually helps your exercise and your body move forward faster. It feels better along the way, too.