Hi and thank you so much for this query.
I am sorry to hear about what happened to your hand.
From the information you have provided, it is most likely a soft tissue injury
or a subcutaneous hematoma
. Normally it should regress progressively over time to a very small and negligeable size unless otherwise. However, if you think it is rather increasing, then it would be of concerning but if it has been reducing, then please exercise some patience. It should be okay all by itself.
Stay relaxed, follow up with your doctor and it shall be okay.
All the best.
Dr. Ditah, MD