A line in adapter for MacBook pro 2013?

Hi,

I have a MacBook pro late 2013. I would love to record my guitar but it doesn't have any line in inputs, which is extremely frustrating. I know I could buy a pod and all that but money is the issue there. I bought this little thing hoping it would fix this problem but the mic port is very distorted (with a clean amp setting, and plugging in directly to the guitar).

http://www.amazon.com/Sabrent-External-Sound-Box-USB-SBCV/dp/B002R33VWW/ref=sr_1 _3?ie=UTF8&qid=1390926205&sr=8-3&keywords=sabrent+sound+card

I just need to find a simple line in to usb interface. Does anyone have anything they could recommend? I'd be great if you also used it before, I don't want to make the same mistake.

Thanks in advance.