To be honest, I don't think you get thrown into the deep end in first year at uni. There was a lot of foundation learning, which if you had studied that subject at A-level was just a repeat, and marks didn't count towards your degree so all you need to do is pass. You don't need a 1st or 2:1 in your first year. You also have the option to switch courses after the 1st year and you can even retake exams if you do fail one.
Yeh, going with friends would be much better. A lot of people struggle leaving home for uni if they have a really good group of friends and they are going to be dotted around the country so one last hurrah does sound good.
1st year can be daunting as well but you are typically in a halls of residence with a load of other kids the same age in the same boat. If you can get catered halls it takes away a lot of the hassle of having to be too self-sufficient and also gives a good place to meet people if you don't get on with your immediate neighbours.