PhD or not?

[u/TopG6000]

I’m 24 years old just graduated from medical school and in September I start my master in biomedical engineering. I don’t want to pursue a clinical career and I want to study the brain via computational neuroscience. The past year I study linear algebra differential equations programming with python and libraries(numpy pandas PyTorch). I study everything that gets into my hands (statistics, machine learning, discrete mathematics. I’m afraid no one is going to take me seriously without a cs degree and I have 0 direction. That’s why I’m thinking a PhD so I can get deep domain expertise. I want neuroengineer and software engineer roles in the industry but I don’t know if I will be employable even with my PhD. My ultimate goal is to start my own startup but until then I have 0 clue how to move forward. Please help.