Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern. As per your complain and presentation of symptoms headache and severe pain and crackling sound on opening the jaw are all indicative of injury to the jaw joint secondary to the trauma or physical injury.. Nausea and headache can be due minor head injury while swelling is due to inflammation secondary to the soft tissue injury.. As you CT SCAN is not indicative of anything pathological you need not to worry about any deep brain injury.. You should consult an Oral Physician and get evaluated and an Orthopantomogram [OPG] that is a full mouth x ray has to be done to rule out any disturbance related to the jaw joint which is the probable cause of cracking soung on opening mouth and it occurs commonly due to dislocation of articular disc that is a soft cushion between the bony ends of the jaw joint.. As of now you can take anti-inflammatory painkiller Ibuprofen for pain relief.. Take muscle relaxant containing Chlorzoxasone. Do warm alternate cool and warm compresses over the swelling over the temple for faster relief. Take a soft diet.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.