How To Heal Sprain On Index Finger By Lifting Heavy Things?

the inner knuckle of my index finger on my left hand got sprained at work from lifting heavy things. After 2 weeks it doesn't feel any better. It feels like the knuckle is tight or "stuck" and it sends nerve pain to my fingertips and inside my palm when I try to make a fist. Wondering how I can help this heal or if something other than a sprain may be going on.