Got caught cheating on Math PERT

So I made a big mistake. I took the math PERT 2 weeks ago and scored 120 on it where I need 123 to be exempt from remedial math classes so I decided I’ll study harder and retest. Two days ago during the retest I made the grave mistake of using my cellphone’s calculator during the test to make sure I got the score that I needed. I was taking the test in my college’s testing center where it’s on a computer. I did not need to use the calculator at all until I hit question 26/30… I thought I was in the clear until the supervisor apparently caught me and asked me to step outside and confronted me about it. I thought I could flat out deny it so that’s what I did, I told them I wasn’t using my phone to cheat however I did have it in my hand and was fumbling with it while solving my test (hindsight that was a really bad excuse) They didn’t buy it. They canceled my test, suspended my classes and was told I need to make an appointment with the college’s dean to avoid getting kicked out. I have never cheated on an exam before and the one time I did I got caught, and the sad part is I probably would have passed without resorting to cheating.

Tomorrow morning I have an appointment with the dean of my college in regards to all of this. I have absolutely no idea what to do. My entire college education is on the line and I’m scared. I lied and said I wasn’t cheating but now I have no clue how the conversation will go with the dean. Can I please have some advice on how I should go about this?