Right thumb pain may be associated with some soft tissue strain may be due to excessive load. Since you are feeding currently, not many medicines can be started.. It may be sometimes associated with
calcium and vit d deficiency.
Next Steps
I will suggest to start with hot fomentation, take paracetamol tablet if pain is more, start
calcium and vit d supplements, avoid heavy work with right hand..
Health Tips
Avoid heavy activities involving the right thumb..