There is no short solution to coming to terms with sadness. I suppose the best thing to do is to identity the source of your sadness and remove it from your life. Sometimes, if it is a person, or aspect to which we are partial, it is hard to accept that this must be done. In other cases, where perhaps it is a matter out of our control, all that remains is one's ability to accept the cause of the sadness. Then it is a question of whether we can find a purpose or reason to justify or balance the pain.
I can't tell you there is a hope at the end of the journey, or a light at the end of the tunnel. I cannot say it will all be OK. But I can tell you that I believe we all have what it takes to find peace in ourselves, and if you can find peace with whatever it is that troubles you, then you will have your answer.