I want it all

I see how sometimes it can be so easy to give up on the things we want. When you've tried and think you've given it your best but you really haven't ; now am left wallowing in thoughts of what i could have done better or that maybe i was just never meant to have it.
I'm feeling a little deflated, not as optimistic as i usually am. There are so many things i want but feel are out of my reach right now. I also can't shake the feeling that i flanked one of my exams; failure is a small death i tell you! That degree feels so close but yet so far away (sigh).
Why do all the choices we make have to be a trade off, give up one thing to attain the next; why can't we have it all? I know "you can't have the cake and eat it" but sometimes i wish i could...I want it all.
I didn't realise until now how easily we can get consumed by the things we cannot control; how easy it is to get caught up in things gone by,things that cannot be changed.