Take a deep breath. This might be your last. Think of how many times a deep breath has saved you from making a rash decision. Think of how beautiful the rose smelled, the spring air, the crisp winter cold felt. Take a deep breath and recall how you, at one point, took your first breath.
You are dying. There is no way around it. There is no fountain of youth, cure for ageing. There is no way out of death. You can though choose to appreciate this life. Think of all the tastes and smells that crossed your path. Remember the brilliant sound of an influential music piece. Remember your tears, remember your laughter, the ones that you laugh with.
Look around you right now. No matter where you are there are things that you will miss when you are gone. Find a way to honor those special things. Spend time honouring, leave the complaining for when you're dead. Dead people are the best complainers.
If you can not find gratitude for being alive, no matter how tough it gets, then stop whatever youa r doing and find one second of gratitude for being alive. Find one thing worth living for. Connect to that thing and build upon it.
Be alive, for soon you will be dead.