When you come into the gym and already put a limit on the amount of weight you'll lift that day ("135 is SO HEAVY, there's no way I'll get past that!"), then you're limiting both your performance that day and your potential growth over time.
Instead, I'd suggest removing preconceived notions about your capabilities. Come into each workout with an open mind and the intention to do the best you can. Listen to your coaches as they tell you what to expect and how to approach each workout and follow their suggestions.
Be positive in your mindset and your progress will speed up. This doesn't mean that you can't have bad days; it just means you shouldn't let bad days hurt your feelings.