Missing one credit to graduate May 2020

First of all I had some trouble applying for graduation b/c on October 2019, I selected to graduate on fall of 2020. I blindly assumed that I would not graduate on spring which I assume was early Jan - March and fall was around June - August. Yes I am stupid.
So I tried to ask for a diploma and even ecertificate but could not find it. So I contacted the school of record’s and realized that I did not choose the right graduation “term”. So I fixed it to the soonest possible option of summer 2020.
However, the main problem becomes apparent. Record’s office sends me an email saying that I am missing one credit for graduation requirement.
At first I did not believe what I was seeing. I was thinking well there must be an error in the system or credit that was unaccounted for.
When I went to check the number of credits I was indeed missing one credit.
I was overwhelmed with this shocking feeling and was in denial of the situation I am in. It was hard to keep my sanity since I thought I would be done with college on May.
Trying to stay calm, I emailed admissions office, academic advisor, dean of students, and everyone I could think of who can provide me with anything that can get me out of the misery I am in.
And when I tried to figure out the starting point of where the mistakes could have happened, my memory brings me back to the time where I have visited my academic advisor. I went to see academic advisor on early spring when the second semester had started. My academic advisor told me that one course (3 credit) that I have selected which was a second eight week course did not meet the requirement. So we found another course (2 credit) to replace my second eight weeks to fulfill the requirement. At that time I was wondering if this would fulfill the requirements and allow me to graduate on time. I do not recollect if I asked my advisor directly after replacing the 3 credit course with 2 credit course whether this will allow me to graduate on time. The main purpose of the visit with my academic advisor was to “check if I would graduate on time fulfilling the requirement” but I did not ask my academic advisor whether this was the right decision to graduate on time; I think I just blindly assumed that I would be fine.
I did not know that not speaking up my thoughts that moment would bring me to a dire situation. I know people would say “you are responsible for managing your credit hours and requirement to graduate” and I would agree. but the bitter truth is hurting me so much.

As of now, I am looking for ways to fill up the missing credit. I will probably take the summer course for the university or ivy tech. If I think about it money wise, I would have invested the same amount since university will charge according to the credit hours. (idk maybe I will get taxed with additional random charges just for taking one course)
I also inquired about the CLEP option where I would take an exam and if I get the passing grade, it would be counted towards the credit. But surprisingly not a single person that I contacted knows about this. The website does show that you can get credit for passing AP class or CLEP exams but I don’t know if this is applicable for senior undergraduate.