Hello
Transparent teeth means....Enamel z wearing off....hv multiple reasons....due to
Acidity
Soft or hard drinks
Habits/smoking
Vigorous brushing
Professional hazards (working in chemical/gas factory)etc
Which causes thining of enamel n leads to sensitivity
Blackish teeth ....also hv different reasons n causes...tht means becaz of thining of enamel...its absorbing stains
Could b from...tea/coffee/tobacco...etc
Next Steps
visit near by dentist as soon as possible...since u hv been experiencing it from last month...condition shouldn't deteriorate more
Health Tips
avoid very hot or cold food
get rid of habits if any
pls get ur complete treatment done...not just sensitivity or blackish ness but also
aesthetic n cleaning of teeth