Extremely slow internet

Hello,

This is going to be a long post as I describe mostly everything what happened I apologize for the long post and please bear with me.

I own a macbook pro(running OSX mavricks) and an Alienware laptop(Dell running windows 7) to play games on.

I was originally using VPN connections to play online games from the place I rent.
I disabled the VPN so that I can upload a youtube video but then I decided to enable VPN while uploading because I wanted to play games while waiting for my video to upload and I was also viewing a live video stream on my macbook pro at the same time.(I enjoy our high speed internet and I tend to do multiple things at the same time)

I suddenly notice that when I refreshed the page on my macbook that it said on my browser "webpage cannot be found" and I also noticed the same thing happening on IE on my alienware.

Both computers had the same issue of everything but the browser not connecting(skype working,online game running etc.).
I thought at that time my landlords will be upset with not being able to browse the internet.

However I noticed that when I turn on the VPN that I am able to browse the internet so I quickly Google searched a solution to this problem and the first hit was here:

https://ccm.net/apps-sites/web/1653-how-to-fix-browser-if-pages-won-t-load/#221

and followed the steps of Rodlee's post(thank you Rodlee)
so I type the commands into cmd on my Alienware laptop:

netsh int ip reset resetlog.txt
netsh winsock reset

I thing I typed both commands at the same time restarted and I have solved the issue and was able to again browse the internet on both on my macbook and alienware.

AND here is where the problem is: the connection speed has now become extremely slow that I am getting 0.12Mbps download speed and 0.37Mbps upload speed with 500ms latency on all computers and mobile phones.

We normally get something like 10~20Mbps download speed and we are running VDSL.

I tried resetting the router, looked for other solutions on google and found some other commands and I typed it on cmd:

netsh int ip reset resetlog.txt(I tried twice to see if changes anything and it didn't)
netsh winsock reset(I tried twice to see if changes anything and it didn't)
netsh int ip reset resettcpip.txt
netsh int ip reset reset.log hit
netsh winsock reset catalog
netsh int tcp set heuristics disabled(enabled afterwards because and nothing changed)
netsh int tcp set global autotuninglevel=disabled
(set it back to normal afterwards because nothing changed)
netsh int tcp set global rss=enabled(disabled afterwards because nothing changed)

and nothing had changed and even now turning on VPN has become very slow too.

I done little bit of programming in the past but I have limited knowledge on networking and I admit that I don't really know what I'm doing. I tried reading about these commands but I don't quite understand.

I shouldn't have messed about with something I don't know and I now regret it.
I have now spent about 2 days looking for solutions and this is doing my head in.

The only way now perhaps is to contact the ISP or replace the modem which will be a hassle.
I don't have the username and password(the internet is not mine) for the modem so I can't access the settings it at this stage.

I am just trying to undo what I have done to get the normal speed that it should be at.

Any help will be appreciated.

I will update if we do contact the ISP and if the problem gets solved.