Hi Maddie
I faced this problem around 3 months ago and tried every thing under the sun including interference my internet provider and computer technician plus many other things like changing drivers and sittings .
Finally i decided to change my internet provider who supplied me with new router and the minute i installed the new router the problem was solved instantly .
I suggest you take your PC to a family member or friend house and try it there and see if it will find and connect to their routers or not , if it does that then you know it's your router/modem .
Wish you good luck