A'ight - let's talk about getting better...really, at anything, but I'll try to keep it mostly to visual art.
AA has it right - the first step is acceptance. You have to accept you have a problem. Your art isn't where you want it to be. Dash it all! It sounds funny, but I went to art school with someone who couldn't see this. What he was seeing himself doing in his mind was not what was coming out on the paper, and he was believing his mind. Particularly if you've grown up feeling special and loved for your artistic ability, it can be hard to admit to yourself that you aren't where you want to be.
Of course, that's the tip of the iceberg. "Not where you want it to be." is completely useless for problem solving. Gotta dig deeper. I have no idea what your specific sub-problems are, but in general, we can break them down into two categories, problems in what you are trying to do, and problems with how you are trying to accomplish those goals. Most people will have both.
For art, I think we can usually reframe those as "Skill Problems" and "Tool Problems."
Ok, so you have skill problems. Probably, you're going to gravitate to an obvious one that doesn't really scare you that much, but you think does. For a lot of people, that seems to be either perspective or anatomy...chances are, your real problem is only slightly related to those things....dig deeper. Is it anatomy you have a problem with, or is it an understanding of how to represent 3D organic shapes in two dimensions? Is it shape representation, or the fact that your line quality needs a lot of work? Maybe it's understanding foreshortening? Maybe it's visualizing dynamic poses? Whatever level you can finally drill down to, I can almost assure you it won't be "anatomy."
Same goes for perspective. Many of the same sub-problems, as well as lighting, composition, understanding architecture, understanding plantlife, understanding rock formations...fixing your perspective is probably the least of your problems.
Tool problems are in many ways, the easier ones to solve...problem is, we often try to solve them instead of solving our skill problems. Everyone keeps looking for the perfect software, the perfect brushset, or the perfect paint brand. In many cases, these things will make a slight difference, but not much...the trap is that this is where you spend all your energy.
All this can be pretty discouraging. Every time you find something to work on, you're going to start chipping away at it and realize your issues are much deeper than you feared. This is another one of those cases where you have to be able to hold two different perspective simultaneously in your head. You need to know what you need to do to improve - but you also need to put that shit aside and get on with making stuff. If you only focus on what you need to know, you get trapped in what my father called, "The Paralysis of Analysis." If you ignore thinking about your weak points, you aren't going to get better very quickly.
I tend to recommend a 30/70 split. Try to spend 30% of your time doing deep focused studies on your weak areas. This is when you do master copies, or gesture-line drawings, or line quality exercises, or draw boxes in perspective, or whatever targets the specific thing you are working on. The other 70%, try to apply those things to full on pieces you are working on. Apply the techniques you are studying.
For tools - 30% of the time, try using a different tool. Uses brushes you aren't familiar with, or pens if you are a pencil person, or watercolor if you are an oils artist. Focus on how the different tools respond differently to different desired outcomes. This will help you learn new tools, which is great, and it will probably give you a better understanding of your current ones, which is even better.
Again, all of this goes back to - Find what your real problems are. Fearlessly analyze your weaknesses, to see if they really are the things you think they are, or if they point to deeper, more hidden issues. Embrace the fact that you don't know, instead of trying to pretend you got this and everything's cool.
Thanks for reading! Keep fighting the good fight :)