Yes you could do that, and I don’t see why references from college wouldn’t work.
Why are you in pharmacy if you don’t intend on continuing it? Is it like a backup plan if you don’t get into medicine you will continue pharmacy?
If you only changed your mind recently, maybe going to an open day and speaking to a professor could help you make up your mind better?
And if you do start medicine you probably need to restart a year one which means you are taking on more loans.
My university has a if you drop out before Christmas you get 75% of your tuition back so check if your university has similar.
I do know a lot of people who switched unis after foundation year/first year but they all chose the same or very similar field. It might be tough for you.
Good luck!
Best, Maddie (Kingston Rep)