Do you know the classic grounding technique of 5 things you can see, 4 things you can touch, etc? I did the same but with emotions instead of senses:

You have to imagine 2 situations that make you feel each emotion, I usually do happiness, shame, love, anger, and saddness (I leave sadness for the end because it's the one I tend to repress the most).

You must imagine it with clear detail and focus on it until you can actually feel the emotion.

After that, you can make conclussions about which things are important for you in life. For example, if your best friend makes you happy and failing a test makes you feel sad, friends and study are valuable for you.

When you finish you will have gotten rid of the feeling of void, and you will feel you have a purpose on life. I hope this helps you!