I'm sorry you're having a hard time I've definitely had my moments where I'm so sad for no apparent reason. Can you pinpoint the source of your sadness?

One of the most helpful skills/concepts I've learned in DBT treatment is "riding the wave" and knowing that overwhelming emotions ebb and flow... you can't cry and be sad forever (although, trust me, I know it can feel like it-- especially in the moment). This is hard for me to do, but just know that relief for your sadness will come, even if just for a short while.