Multiple devices connecting to my router but say no internet. Only laptop is getting internet.

I'm not sure what model my it is but it's a router modem combo. It just says netgear24 on it and my provider is xfinity. Randomly stopped working when it got hot almost a week ago. It just started cooling off but still doesn't work. I usually use my xbox one and phone to connect to the wifi and use it, but it started saying it was connected with no internet. Weirdly when I turned on my computer it connected just fine. I checked my conncetion to xfinity online and it says it's totally fine. The router seems fine, all the lights are lit up, not like when it normally crashes on me. BUT I tried restarting it anyway. OVER AND OVER AGAIN. I even left it off overnight once. I logged off the wifi, restarted all my devices, and the router, and THEN tried logging back on. Nothing. I've tried looking up what could be wrong, but I'm not tech savy and don't understand any of it. I don't know what to do. Is there a fix I'm missing? A problem with the router? I don't know what I'm doing, tech isn't my thing. Or do I need to buy a new router modem combo to replace it, or will THAT even fix it? I don't even know where to start. Please help!