Scottish: An Accent or A Language?

I spoke on the phone with my landlord in Scotland for the first time today, to ask what the exact address of my apartment would be. We talked for about 5 minutes total, or I should say, she talked for 5 minutes and I periodically said "uh huh" or "excuse me?". I probably only understood 20% of what she said, and for a minute or so in the middle, I think she might have been speaking a whole other language. I'm not kidding even a little. She must have thought that I was retarded, because just to get the address correct (the only reason I called), I had to have her repeat it 3 times. I was so embarrassed by the end of the conversation that I started just saying "uh huh" to everything. I might have been agreeing to pay double rent, or telling her that, yes, in fact I have been convicted of a felony. Who knows what she was asking.

Now I'm fairly concerned that even though I speak English, I don't speak Scottish, or whatever it was that she was speaking. I had always assumed that it would be the exact same language except with a sexy accent and cute little terms for things (jumpers, knickers, neeps and tatties), but now I'm starting to think I was wrong. Am I going to a country where I won't understand 80% of what people say to me? I'm going to need ESL classes when I get there...