"Self Pity: I never saw a wild thing sorry for itself. A bird will fall frozen dead from a bough without ever having felt sorry for itself."
I got that quote from a movie, but it is true.
There is one problem I have with your post though.
You must like yourself with all you failures and that is hard. But if you accept your own person, you will become happy.
Aside from the grammar, I must say, OBJECTION. Happiness does not come from staying still and accepting your weakness, it comes from accomplishment. One must realize their weaknesses and work to replace that weakness with strength. As proof, Benjamin Franklin took a path towards moral perfection throughout his life, and while he never reached it, he commented in his autobiography that he was a better man and lived a better life because of this.
If you're a failure, then go and become a success. If you don't belong anywhere, then make your own place. Do not covet other people's success, for you are missing something of greater value inside yourself.
Yes what I said was extremely cheesy, but this is how victory is obtained if you believe in it. Furthermore, do not get prideful. You should not just rely on flimsy self-esteem, but you should esteem others, as they shall esteem you.
These are the truths that shall set you on a path of strength and happiness. It is not a path where you say "I am weak, but I'm okay with it", it is a path where you will say "I was weak, but I have overcome it". Yes it is a hard path, but if it wasn't ,it's rewards would not shine as brightly as they do.