Thanks for your query.
From the given description, I feel that you could have sustained a SPRAIN
of the Metacarpophalageal joint (MCP joint). Either the capsule of the joint or the ligaments might have suffered injury
due to overstretch.
The Acute management of this condition is as follows -
* Rest to the local part - by avoiding any further movements that puts strain over the MCP joint.
* Ice packing - to instantly reduce the pain & swelling. Cold
compressions should be kept for atleast 15 minutes and should be repeated every 2 hours.
I think the above measures will temporarily take care of your symptoms. For definitive diagnosis and management, you have to consult an orthopedic surgeon.
I do hope that you have found something helpful and I will be glad to answer any further query.