If you have your owner's manual, review it or try online ; https://manualsfile.com/download/b2m76hmll.html. I don't know if there are two fans (one for freezer, one for fridge). Water lines are engineered carefully to avoid freezing issues. According to your update, freezing occurred to the water line suggesting a possibility of the defrost heater, if equipped, may be faulty or electronics isn't cycling the heater to keep freezer coils from building up frost blocking air flow. If one fan, check it for operation, holding the door closed switch if necessary while observing for fan operation after the door closed switch is pushed in to fool the electronics into resuming fan operation. You may have to leave the fridge door open for a few minutes as warm air enters for the fridge temperature sensor to detect warm air to trigger the fan. Under most circumstances, refrigerator repairs are not diy friendly unless familiarity of electronics, computerized system and/or refrigeration.