One of the things my early teachers in the martial arts said, that I have seen repeatedly over the past 20ish years of teaching martial arts, is that everyone goes through phases where they feel like they aren't learning, or are even getting worse.
Often, what is really happening is that the mental development that is part of learning a martial art is outstripping the physical skills development, so you see problems that you were not aware of faster than you can resolve them. I call this the green belt disease, because almost everyone hits this at about green belt level (1 and a half to 2 years at 4 hours training per week). That increased self awareness is actually a good sign of learning.
Also, at 14 your body is still growing rapidly. Your balance and timing will be off to some extent. When your body stops growing, your physical skill level will quickly match your expectations.
With that said, it is entirely possible that the club you are practicing with is entirely too focused on the high level competition for where you are at now. If you like the people and organization, you might want to talk to the instructor about finding a feeder club to start at a level closer to where you are at.
If you have no particular ties to this organization or system, there are many good martial arts clubs out there. Most serious martial artists have trained in more than one system. I feel it important enough to get input from people with backgrounds in different styles that our club hosts an annual rensei - a tournament format event that encourages and requires the "judges" to coach the competitors. My students learn things from other teachers that they will never learn from me.
At the same time, I believe it is important to focus on one art until you have basic proficiency (first black belt for example), before diverging too much from your roots.
If you are looking to transfer your existing skills to another art, TKD is most similar to other Shotokan derivative arts, followed by Shorin ryu karate and hard style kung fu systems.
Good luck, and don't give up.