@boolani
How long ago did you fall? How did you fall and from how high? Did you fall on pavement or inside the house on the floor? Did you injure anything else?

You may want to make sure you didn’t injure anything more seriously and see an orthopedic hip specialist. You may want/need some imaging done. You could have torn a gluteal muscle/tendon.

Have you tried rest/ice and anti-inflammatory medication (like NSAIDs/Motrin/Advil)? Have you tried topical Voltaren gel to reduce inflammation?

1. https://www.verywellhealth.com/what-is-a-butt-bruise-5214636
2. https://www.medicinenet.com/gluteal_injury/article.htm