The saddest thing is when you are feeling real down,you look around and realize there is no shoulder for you. That feeling of emptiness like the world has drained you of everything you had. For you to feel this sad you must have once felt so happy .
It is good to cry and let everything out,crying will help eliminate toxins and cause hormonal shift that enable the stress level to lower. Always pick a safe place and allow yourself to cry .
Find things that you can do to improve yourself and bring out a better version of you. Keep yourself busy in such a way you lack time to dwell on the problem you are encountering. Go to the gym and get in shape or read books to improve your skills.
Talking to someone you trust about the problem can help ease things. They might provide a solution to the problem or cheer you up. This might help lower the stress.
When you are sad it is difficult to engage yourself with something you love doing. The good thing is that once you start doing something you love,you will enjoy it. It reduces the feeling of sadness. If you love music listen to it,if you love cooking plan on the recipe.
You have to acknowledge your feeling first in order to deal with it.