The setting which determines how long your browser spends trying to connect to a site is probably hidden deep within the techie stuff. Unless you really know what you're doing, it's not always wise to muck about in there. Further, since you've not told us which browser you're using, it's hard to point you in the right direction anyway. (In Firefox, and possibly other browsers too, you can access the techie stuff by typing 'about:config' in the address bar and hitting 'Enter' - but it's easy to mess things up in there!)
Things to try:
1. If your computer is connected to your router wirelessly, try using an Ethernet cable instead. (If things suddenly improve you'll know that its a wifi problem) ;
2. Clear your browser's cache:
http://www.refreshyourcache.com/en/home/
(I was experiencing lots of problems getting content-heavy sites to load in Firefox. Clearing the cache fixed the problem for me) ;
3. Try using a different browser. e.g. if you're currently using, say, Chrome, try Edge or Internet Explorer. (If things then get better you'll know that it's a problem with your default browser) ;
4. Check your broadband speed here:
http://speedtest.btwholesale.com/
(That's the official test site where the cabling to your home is provided by BT, irrespective of which ISP you use).
Alternatively use this site:
http://www.speedtest.net/
(If you get really low speeds you'll know that it's a problem with your broadband connection).