Things doesn't always go as planned, and you're either sad or mad that's fine, but never run from the emotions, because that's when you're trapped.
It's important to feel it is "ok"...It's "ok" that you forgot your schedule. It's "ok" that you failed at playing the guitar. It's "ok" your relationship didn't work. Did you die from it? No.
I believe the universe is already then making a new path for you to step on. We always swim along the current, even jump sideways sometimes. In the end there's thousands of paths the universe has opened for you, and which path is your choice to make.
It doesn't mean you will always succeed, that's why I feel it's "ok". I tried and found out this wasn't for me, now I take a step into a new path. Until I've found my own Milky Way.