Your teeth are severely malaligned. The sensitivity could be because the teeth are causing trauma to each other as they are not contacting properly. This results in wearing away of enamel and hence the sensitivity.
Visit your Orthodontist for aligning the teeth and getting a better smile. The sensitivity issues can be handled along with.
Dr. Vaibhav Nepalia.
Your sensitivity problem is most probably related to your malocclusion or improper alignment of teeth. Teeth with improper alignment leads to more plaque accumulation, besides brushing twice , that ultimately leads to all sorts of dental problem like cavities ,bleeding gums and sensitivity. After looking at your intraoral photographs I will recommend you to go ahead with braces/orthodontic treatment for healthy dentition and beautiful smile. Waiting for too long might leads to emergence of other dental problem like cavities, gingivities, loosening of tooth etc.