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Uni Choices!!! Need help on what course I should pick in uni

So currently, I am in my first year of college and nearing the end of the year and we will be starting the ucas process on wednesday. the thing is, I don't have the faintest idea of what area i want to go into when going to uni. I don't know if I want to go uni. because of the cost and stuff.

I am doing btec business level 3 diploma and as level media studies. I have suddenly found an interest in forenisc science or audiology which is basicly people who fit hearing aids on and I feel as if i want to do it in uni but it requires you to do at least 2 science subjects at a level, full two year course. in my college you can stay up to 3 years if you fail a year so doing an extra year at college wouldn't be a problem. the problem is that I am scared that if I do do the science subjects but fail in it then the 3 years I did in college would have been a waste. I need to know other peoples opinion other than my family and friends bcuz they only say that I should only do what I wanna do or what might be best for me.

Another problem is that my parents won't let me go to a uni very far away and want me to go to a uni in my own city or close around.
I really need help and advise on what I should do before it gets too late and I finish college having no idea what I am going to do with my life.