Internet speeds are very slow

I have the U200 acct. My internet is to slow. It's so slow that now I only get on my laptop for short periods. I'm using a unlimited T-Mobile phone acct so it doesn't make since for me to upgrade and pay more money. But I can download get up walk around and come back and it's still downloading the site. I've looked at simple solutions and most don't apply. I'm directly in front of the box for the signal. There is just me using the service etc., etc. I have McAfee security. My browsers are deleted etc. The speed is the issue not coming fast enough in this old bldg!!