If you could write a note to your younger self, what would you say in only three words?
I had two thoughts. 1) Words can hurt. 2) Try your best.
What would your note say? 
Don't do it
"Nothing lasts Forever."
Rescue Yourself First
It's okay to cry
Change your ways.
You're not alone!
More details: there are people out there that love you, care about you and will support you. If you can't find them now, you will find them sooner or later. Also if you feel like you're the only one suffering in a specific situation, then think again, because... you're not the only one!
Happiness comes again
sadness does too :(
And that's how life works. You can never have a perfect life. If everything was good, and you never experienced sadness - what value does happiness hold? Live life for all its moments whether it be good, bad or exceptional. The darks days will pass, and they will return, but that's life. There will never be a day where you can say "From now on I will be happy", because true happiness comes from accepting the good and bad in the world. If you can't change your situation, change your attitude about it. Eventually you'll learn to dance in the rain and feel the blessing of the sun.
don't be afraid to start over,no matter what people say...follow your heart and leave that source of unhappiness behind.
You wasted it.
