I'm about to achieve my bachelor's degree, but my life feels directionless and hopeless. Anyone share this feeling?

I'm a 24 year old male, diagnosed with ADHD inattentive since freshman year of high school. I am currently working towards a pre-med degree at my university where I am on track to graduate in June. For the average person, I'd expect this privilege to be an exciting event into the next chapter of their life. However, I am terrified. Throughout my college days, I have felt nothing but disappointment in my achievements and although I know that I am capable of much greater feats than I have allowed myself to accomplish so far, I fail to find motivation in everything that I try. I skated by on a low B to C average in every course with an occasional A through in there a few times. Ultimately, continuing my education to specialize in some medical degree would be ideal, but from my research, no respectable school would ever admit someone with the grades on my record. I consider myself fairly intelligent, but lack the motivation and drive to perform at any level greater than average. It is infuriating to me and I fear that my lack of motivation will land me in McDonald's one day. My degree on its own is worthless without a degree of higher education, and even if on the off chance I got admitted into a medical school, I can't shake the thought that I probably wouldn't have the motivation to succeed. Once I graduate, my life has zero direction and I strongly fear for my future. Can anyone relate at all and if so, how did you get through this agony?