Suffering from wetdreams for 7yrs, whether it will decrease sperm count and cause infertility?my penis is small, semen like water, will affect marriage ?

Probably not: The wet dreams and emissions should not affect your fertility. Men w/ poor semen quality can have a problem if daily or more ejaculation but this is not likely for you. The quality of the fluid can be misleading but a semen analysis will answer the question of "quality". Even small penis unlikely to be a problem unless you have unsuccessful vaginal penetration. See urologist is concerned. Best.