don't worry, you'll definitely find people who you can socialise with who are your age - a friend of mine is also going back to college this year who is also 19. she recently went to go do a baseline test at her college and found at least 10 people who are her age and she said she found some people who were even older. its not like theres a 20 year age gap so you will 'fit' in. college is more diverse in terms of the people that go there so you'll defo be able to find people who you can socialise with
i personally think you should do the fashion course. you need to do something you love to do and if you're not 100% sure about english then don't do it at uni. you're going to be investing time, effort and money into a course you dont even like. why would you do that? save your student loan for when you go to uni to do something you actually like