Suggest Remedy For Pain And Stiffness In Fingers

Hi, I am 23 years old and I have never felt this pain before. I have this pain and stiffness in my fingers` joints for a week. I don`t know if it is a coincidence, but I think that the pain started right after I started working as a dishwasher in a restaurant, where I was lifting heavy dishes. I worked there only 3 days and I quit because it was too hard for me. So, I was expecting that the pain will go away, but it only gets worse. The last 3 days I am waking up with stiff fingers and when I try to move them or flex them I feel a lot of pain. As I go through the day the pain becomes less intensive, however, it doesnt completely go away. I started to search online for my condition and I only get confused, the first thing that appears is arthritis, but the thing is, I don`t have pain in my knees, shoulders or wrists, just in my fingers. And they are not swollen or something. My middle finger on my left hand looks kind of different, like deformed, but I am not sure about this too, it can be only my imagination because it`s not a big difference and my boyfriend thinks that my fingers look fine. Could it be arthritis, or it`s something else? Please help me