Hi.. Thanks for the query. One side of your jaw is stiff and locked, then it can be due to jaw joint dislocation but in case if there are other joints that are also painful then it can be most probably due to Arthritic changes in the jaw joint. My suggestion to you is to consult an Oral Surgeon and get examined clinically so that he can try to narrow down the cause and confirm by advising a Panoromic x ray.. As far as your finger is concerned the area of stitches looks like it is infected which is not letting it heal. It might need to be treated with antibiotics oral and topical. For stiffness in jaw you can take a course of anti inflammatory painkillers like Ibuprofen and muscle relaxants like Chlorzoxasone.. Try to open the mouth under limits of pain tolerance as much as possible.. Avoid chewing hard foods and take a soft diet.. Hope this helps.. Regards.