foundation year at UEA

I already have a place in september to do psychology at UEA. But I was thinking about switching to do environmental sciences or marine sciences. I do not have the required A Levels at all, (english lit, french and psychology) so i would have to do a foundation year.
One issue is, im a gap student, so im already a year older than most people starting this year, so when i graduate i will be 2 years older than most other graduates, and not to mention it's another year of student loans and accomodation costs, and i'm strugglinf to afford accomodation as it is.
do you think this is worth it? has anyone done a foundation year or in a smiliar situation?