Have you ever made something and someone told you that they felt it could be better, or it's not your best work is it? Or they said something that at first seems nice, but in retrospect it was catty and unnecessary, or just plain freaking mean. Making things whether it's a painting, a dress, a story, or a cake, it's all art in some way, and you have put a bit of you in it. Who needs to hear peoples crappy opinion of your work, especially when you are in the initial phases of learning, after all what have they done that's so great.
For a long time other peoples words would fester in my head as I tried to make something better (for them). I just never could and I would feel angry because I felt I had wasted my time. I had trusted these peoples opinions because they came to me as someone I held in esteem whether they were friend or family member. Then someone, one day, made a big mistake and insulted me on something where I reign supreme, they knocked my cooking. I am a damn fine cook, I have been since I was a young girl. I can walk into a kitchen and make something out of practically nothing and make it taste good to boot. Well I looked that person in the eye and I said "Really, lets see you do better." There was dead quiet in the room as they tried to explain that they needed to have just the right pots and ingredients. I just turned to them and in a loud whisper I said "No... I want you to do better with what I had to work with, come on lets see you." I made room for them in the kitchen and they then had to admit they didn't know that much about cooking and they backed off and disappeared, never to be heard of again.
I do not know why people do this and I don't care. However, don't take to heart anything bad that anyone says. For the most part, they are just blowing smoke out their ass, making you look small so that they can look large. It is a shallow game they play and one you can easily avoid by saying a simple thank you, without an explanation. You know where you are with what you are doing, and if you think you are improving, you are. If you think you are in a rut, try a different genre. Do not give up on yourself, practise will improve anything. It took me a long time to find the things I really liked doing and the interesting thing about that was I discovered I was good at what I liked. The more I liked it the better I became at it. I still have a long way to go to be really good, but I am pleased with my progress on things.
I am also fortunate enough to have a partner who thinks it's the cutest thing in the world when I'm sitting on my lazyboy with the feet up and knitting one of my little hats. He watches my progress and tells me those are good enough to sell. He wears some of my hats and sometimes people even want to buy them... It's really odd that the ones people want to buy are the ones I can't bear to part with, (like my completely black santa hat). My partner has talked me into making a whole bunch of various pieces, some hats, some charms, some pretty little bits and bobs, and when I have enough stock, he's going to rent me a stall at the farmers market. I hope that anyone whose had the "you suck speech" meet ups with a person as supportive as my partner. And one more thing to remember, opinions are like assholes, everyone has one, but not all need to be heard or accounted for. When you make art, it is for you, it does not matter what anyone else thinks, all that matters is what you think.
A quick addendum to this little rambling rant, If someone who is good at what you do offers you constructive criticism so you can improve, that is a whole different matter. Even if it comes across as a little gruff, they will show you something for your level that will help your work immensely if you are open to it. Like if Wolfgang Puck slaps your soggy pizza crust into your hand and then offers for you to come to his restaurant and he will teach you to make a proper one, those you just have to jump on.