Even we do have to aim high and achieve more, we should be grateful for what Allah has created for us is priceless and if you make a list out of it you can't really imagine how long it will be. Every single thing on Earth is created by Him and has benefits us as human beings.
Hence, let's cherish on what we already had and going to have in the future as life would be more meaningful that way. For instance, I am perfectly normal physically and mentally, having a loving family that will always care for me, having a circle of friends that I know I can depend on them whether it's rain or shine; those are the things that we always take for granted.
So now, do constantly make as many as possible of positive affirmations (either you write it down or think of it in your mind) and act according to it and insyaAllah you'll find much easier to comprehend them in your life. I'm making mine now, here are some of them:
Alhamdulillah..I am thankful for what I have! ;-)
I want to be a successful muslim insyaAllah!
I will never give up!
I want to finish this life strong!
and last but not least...