Not sure if your a spiritual or religious person or not, but I can tell you what the Bible says our purpose is and the reason for your struggle. But I won't push that idea on you.

The point is, we all have a life to live. And we can chose to either get on living, or get on dying. You either live each day for the moment, as if that day might be your last, or live each day wondering when your last will be.

Take life one day at a time and try to make that day the absolute best it can be. SO that should you wake up alive again the next day, you can try just as hard to make it the best it could be