Connecting desktop to internet

[slaptitz]

I looked online trying to find a solution to a relatively simple problem but all this did was create more confusion so please excuse my lack of knowledge and simple descriptions. Anyway heres the problem:

I have an internet modem thats downstairs but my pc is upstairs (pc doesnt support wifi). I bought a cat5 ethernet cable that connects to both my pc and modem but since they're too far away I cant connect them and I cant bring the modem upstairs because my smart tv is using one of the internet ports. I tried connecting the ethernet cable to the internet socket in my wall but it's too big which is now the second problem. My third problem is the small cable that fits into the wall socket cant reach my pc.

Heres my question: Can i buy some sort of adapter to convert my ethernet into a small internet plug that fits into my wall socket?
OR
If i buy a longer small cable (that fits into the wall and my pc) will that even work? (because I read online that it might not but I'm still confused on this topic)

Once again I apologise for not being able to identify the 'small cable' or 'internet wall plug' because i genuinely have no idea what their exact name is.

 

[jackstrr]

Since distance is the issue with your Networking Problem, you should opt for Powerline Adapters, What they do is essentially utilize your electrically wiring and use it to pass data to and from your router, you might be able to get a free pair from your ISP if you explain the issue but if not then you could easily buy a pair from Amazon.

For more information on Powerline Adapters please vist this link.

http://help2.talktalk.co.uk/what-are-powerline-adapters