“Letting go doesn’t mean giving up, but rather accepting that there are things that cannot be.”

I don't usually give up easily, but sometimes your forced to and it sucks. I recently read something that said 'quit competing with others and start competing with yourself'. I find that I do both, im competitive with others and i am also hard on myself, competing with myself for the best.
I usually refuse to give up on anyone or anything unless im told I have to. I keep forgetting though, that giving up doesnt mean that you dont care anymore, it just means that its out of your control.
I have a hard time accepting that things are out of my control but clearly things are, especially other peoples emotions.
I hate the feeling of giving up a thousand times. Where you tell yourself you'll stop trying and then you push a little and fail. I hate that feeling where your starting back at square one again and you need to prove to yourself that your done trying. Or are we trying by not trying?
Sometimes we hope that putting no effort will show that we are able to move on and live withouht, but i believe that we are trying to convince ourselves of this while still hoping well get what we wanted all along. So when do we ever really stop trying, if were still thinking about it?