40 years ago, younger and more arrogant than I am now (or so I like to think), I had this amazing violin teacher. Some teachers you remember for the rest of your life, and she was one of those.
If I turned up feeling good about my week's practice, confident I was playing it well, she'd often be full of criticism. If I turned up full of self-criticism, she would often remark how much progress I had made. I don't think she was doing it to keep my confidence in check. We discussed it at the time, and both concluded that my critical ear and actual progress were always out of sync.
Over the year, this has helped me masses. When I'm frustrated, and feeling like I'm making no progress, I remember this amazing lady, and I remember that it probably means the opposite of what it feels!
Dunno if that can help you at all, but I hope it does.