Seriously speaking, if you are experiencing that much of an emotional roller-coaster-ride and to a point you are wondering if it is starting to affect your sanity, you should check with a mental health professional.

Serious hobbies aren't supposed to be easy but it isn't supposed to create that much of anguish and disappointment AND without giving you a sense of purpose or a desire to improve.

I realize this is Internet and I should take everything with grain of salt, and I am NOT a mental health care professional, but it just doesn't sound healthy. That's what I would seriously consider doing if I was experiencing that much of problems.