You need to do some experimenting on your own to better determine what is going on. Events like this are sometimes a family a matter rather than technological, so ask your father, or whoever serves as network manager for the family, for help in solving it.
The first technological investigation to do the next time this happens is to move the computer that gets booted right next to the router to eliminate wifi interference or low signal strength as a cause. You can also double check that your computer and the phone are set up to gets IPs from the router through DHCP to eliminate an IP conflict as the culprit.
One option is to bring the internet connection closer to you. If you can, run an ethernet cable from the router to your...