As per your presentation it seems that you have inflammation in the 3 rd molar region which is possibly because of impacted tooth , , this inflammation causes discomfort in opening the jaw pain Trismus as well as clicking sound in the TMJ (temporimandibular joint )
Next Steps
You can go for antibiotics( ornidazole and ofloxacin ) to reduce inflammation as well as analgesics( ketorol dt) to relieve pain !
Health Tips
You can also use betadine mouth wash with 2 drops of hydrogen peroxide , or visit the dentist he can irrigate the area with these solutions which will provide you relief ! Take care