I did the same thing! Telling yourself that you're delusional is not right, I was wrong for saying that. I was saying I was delusional because I chose to ignore it, and go along with it. That may be what you are doing now in a sense, but its not too late. You will find peace. I am so glad that you are painting! I wish I was involved in something constructive like that when I was your age. Don't be so hard on yourself though. It doesn't matter what other people think your painting looks like, its YOUR expression and it has to mean something to YOU. Who knows you could be the next Da Vinci or Picasso! I know they were not appreciated in their time and they were very depressed too. But out of their depression came the art and I am glad you are expressing yourself, and best of all posting here!

As for why it is so hard? I don't know. It is still hard for me and it has been so many years battling bipolar. All we can do is be there for each other, and find comfort in knowing we are not alone and try and work through things together.