Write down everything you are sad about
If you are going through grief right now I really hope that you have a friend you can talk to. I hope you have others around you, supporting you in different ways. I hope that you are receiving some kind of professional help.
Even with all that, if you find yourself feeling sad and with no one to talk to at a given moment, then take a piece of paper and start writing down.
Write down your thoughts, your feelings, everything. The more you write about your grief, the more you will get to know yourself and the things that trigger you and the things that help you heal.
All this information is important and I definitely encourage you to share your writings with your therapist.
You can also share what you wrote with a trusted friend if that feels right for you.
And if nothing else, writing will help your healing process.