I want to tell you that you've progressed over time and your skills have become closer to an accurate expression of your skill. Does that mean you've reached your goals? Of course not. It just means that you have gotten better and that you should keep going! I know it gets tough when you're exposed to awesome talent from all ages and backgrounds on a daily frikken basis, but look what you've done and where you've come from! Think about what makes you happy about creating art, what gets you inspired. Think about the "chicken soup" of your work-- the same concepts you return to when you want to remember a time in your life when drawing was fun. Put on some inspirational music, or music you associate with doodling. Draw other characters or revise older pictures. Don't draw to make a masterpiece-- draw to make yourself smile! Don't draw to impress-- draw to express or to entertain. Have fun with it!
Why am I going into this motivational speech? Because sometimes, we meet a harsh, unwanted, overly negative critique that brings us to the point of wanting to give up. (Sometimes we are our own worst critics. Sometimes it's someone who means a lot to us who doesn't know how much they hurt us with these raw, thoughtless criticisms.) We'll grow thicker skin and we'll be able to take these comments and either work with them or ignore them-- but often times, that comes later. For now.... just try to remember what I said. Find the enjoyment in your art.
... And, if it will really make you feel better, just hold a grudge against that person and don't show them any more of your art. They're a bastard anyway. They don't deserve to see your awesomeness. Fuck 'em. XD