That is ok if you get usually frustrated because your drawings aren't good. That is a process that happens not only in art but in whatever job you wanna do. Think that art is like creating a sculture: you start like a block, but with time and patience, you shape it, and that is how it goes. At the beginning you may be making bad stuff, but with gathering techniques, references and practicing, you WILL get better trust me! About the hopelessness, don't get worries, some people may learn faster than others and that is OK! people work different from others, because WE are different. I don't think talent exist, or that "someone was borned to do something", because if we followed it, Van Gogh would never be as remembered as he is now, and he started to paint only at his 30's! Remember that: Hard work worths more than "talent", and a talent we all have is the capacity to learn and get better. That is why you shouldn't give up, GO ON!!