Being arrogant is a curse. When you're arrogant, other people enjoy it when you suffer. Seriously.
Unfortunately, you can't just decide to be humble. When celebrities say, "I am so humbled" when accepting an award, they aren't actually humbled. Deciding that you're humble is just being arrogant about your humility.
So how do you practice real humility? Being embarrassed by forces outside your control. People tend to work hard to make this as infrequent as possible, so it's really valuable when it inevitably happens.
Embarrassment will still be painful when you remember to be thankful for it, but it will be more like weightlifting pain and less like I-want-to-end-my-life pain; it still hurts, but you also feel good because growth is a pleasure and you know you're on the right path.