Veteran Career Changer with great science GPA..but 13 Failed classes coming back to haunt me

I was the typical “I don’t know what I want to do” type student in college and wasted a lot of years not taking school seriously. I failed and withdrew from so many classes and those decisions are coming back to haunt me. As a psychology major who finally figured out where I can serve best, I’ve displayed an awesome upward trend in my last credit hours.I took Biology and Chemistry and got an A and a B but my earlier non science failures are hanging over my head.

I’m leaving active duty service to soley focus on post bacc options and continue to build up my extracurricular activities. My question is, would a formal post bacc offer more credibility and help me avoid doing an SMP? Would it be better to plan on doing a DIY post bacc and do a SMP? It took time to make these mistakes, and it will take time to overcome them. Looking for the most efficient way to move forward. Thanks!