Don't cry over the past, it's gone. Don't stress about the future, it hasn't arrived. Live in the present and make it beautiful.

Each  day is a day that should be lived not only as our last, but as our
first as well. This is not to say that we shouldn't learn from the
experience of the pasts, but we must have a selective memory, because
for many of us our pasts are full of experiences and memories that may
not represent us most effectively in the present.
Make every day a new masterpiece, because as each day goes by, we
should be better able to live out our lives. Each day is a day that we must
live in, and make the best of. Use the tools and experiences that you
have acquired thus far, to help make each step you take stronger, and to
help make each move you make more meaningful. Life will always present
you with challenges, and life will always have a tendency to try to knock
you down. But it isnt about how many times you are knocked down, it is
about what you are able to learn from being knocked down that allows
you to keep getting up and fighting harder.