Go for scaling and do mouthrinses after every meal

yes plaque can lead to sensitivity go for a cleaning . proper brushing technique is required to keep plaque away use mouthrinses

Yes plaque and food deposition can be the reason so undergo checkup, xray and scaling

most probably u may have gum recession bcoz calculie deposition is also a factor for recession its cause your gum line shifted upward leads to naked tooth root in most of case it is major reason of tooth sensitivity better to visit your nearby dental surgeon

Get a scaling done.... It should mostly subside.. If it doesn't u will need a thorough checkup

Get yourself checked by the dentist As soon as possible. U will require a scaling once it is done the situation should improve. If you don't have time to visit the dentist apply (SHY N M) paste over first and second molar where u experience sensitivity. Leave it for 5mins and drink water. If the condition doesn't improve visit the nearest dentist.

visit the nearby dentist for  scaling of ur teeth  and complete dental check up .For sensitivity u can use  vintaj or sensodyne RR. But dental check up is must .