Inspiron 3543- Internet Browser taking forever to open!

Hi, Does anyone know why it would take 15 minutes to open an Internet browser, and then another ten minutes of getting the "Page Unresponsive" message before my Internet will work on my laptop? It's only a year old. There's nothing wrong with my Internet connection- it works fine on my phone, very fast. This happens on wifi and when my laptop is plugged in, and it's only been happening for the last month. It happens on Chrome and IE.

After waiting the 20 minutes or so, then the Internet will work perfectly fine, but I'm not keen on waiting 20 minutes for my browser to open :(

Can anyone suggest anything?

Thank you.