Switching positions?

I work for this medical company in the call
center answering phones all day. It sucks. I have worked there for 3 weeks, this week is my 4th and I'm already miserable. It's literally just me on a computer, in a cubicle, answering the phone ALL day. That's it. It's boring, unpredictable, stressful, isolated, and miserable. My previous job I worked at hospital
and checked in patients in person. I liked that way more. The short time I've worked here my manager has had to call me in her office and corrected me a few times on scheduling patients wrong and minor stuff but I literally have only been here 3 weeks. She's understanding and I'm doing my job but me vs the other new girl I feel I'm doing terrible. I'm also terrible at communicating with people on the phone in general. I'm not quick at responses and struggle with how to respond to situations. Today I saw the company is hiring a front desk person in one of the offices. I'd
prefer to do that way better and the hours are better. I just do not know how to go about the situation since I have only worked there for such a short time. It's just
awkward and I'm not comfortable with my
manager yet. Today I applied, my manager
wasn't there and I was afraid to wait any longer because the position could get taken. But tomorrow she's going to be there and I don't know if I tell her before she finds out or let her ask me about it.. I just don't know what to say... what would you do if you were me? Is it acceptable to say, "I just feel like I will do better working with patients in person like I have done in the
past" if she asks about it? Or should I say
something before she finds out.. I don't know what is a good way to handle this situation?
Switching positions?
3 Opinion