Internet connection lose 5 times a day?

[Noodlez]

Hi so i have Comcast internet the triple play etc.. with power boost now my internet connection has been fine for a while, just this one day it lost the connection to my internet and my brothers computer also and now its been happening for about 2 weeks of constant connection lose but when i restart the computer it works, now my computer connected right to the modem. And also my Ip adress has changed for some reason also, my friends are telling me to get a new modem b/c this one might have died out. the Modem SURFboard Sb5100, if one of your answer is to replace the modem which one shall i get? TYVM.