DO NOT BE SCARED OF FAILURE!
When you fail at something don't get annoyed or frustrated. You should actually take it as a learning experience. Think back to what has happened during your day and see what could have been the cause the failure. Then fix it for next time!
For example if I look back at my day today- I had already done a session today which was taking a 45 minute spin class (making the legs fatigued), I hadn't really eaten enough before my session and the session was also rather rushed. So these are the things I should try to fix next time!
As you can see from my videos failure is part of progress. The first video (failure) I was aiming for 2 reps but only got 1. This was my 5th set and was when failure first happened! (140kg)
I then decided to drop the Weight down to 110kg and rep out with good form! This can be seen in my 2nd video which set 4 of 10 reps.
Still progress in the big picture!