Please help, my hamstrings never heal

i do martial arts all the time. nobody ever seems to have a definate answer about what i should do. some say ice, some say heat. and i never feel it when it happens. i only feel it 1 or 2 days later. people tell me to stretch, but that seems to make the problem worse. i do high and streneous kicks all the time.

i realize that you will most likely not be able to answer my questions to the detail i want, so i was hoping you could direct me to a specific book or books i should read.