Please answer,read detail...in need of desperate help?

So last night I went down on my girl friend for the first time(it was my first time doing so) but I was only able to go down for about 2 seconds because there was a weird smell and it did taste a very sour when I licked it,its bothering me because I went down like 10 different times due to that I would stop so fast. I don't know if that's the way a vagina smells and taste or if it's just her hygiene...please help!?!?!?!