Browsing through the Internet, I stumbled across another iteration of the old "which is better for self-defense, Boxing or Muay Thai?" question. No matter how many times I see it, it always strikes me as an odd one. Not because one is inherently superior to the other, but because neither one actually addresses the issue at hand (surviving a violent assault). Both provide qualities that might be useful in a violent assault, depending on what that assault looks like. In other words, either one might help, or it might not. But neither of them is actually trying to solve the problem?
I wonder if athletes outside of martial arts and combat sports do this. Do you get people asking "I really want to be good at football; should I play basketball or run track?". Do aspiring chess players try to decide between checkers and go?
If your goal is to learn how to defend yourself against a violent assault, spend your time studying violent assaults. How they happen, why they happen, and how you can survive them. There's research out there on the subject, if you go looking for it. There are people who study it, if you seek it out.
The flip side is also true, by the way. If you want to learn how to box, learn how to box. Don't try and modify your self-defense system so that it works for boxing. There are people out there who already have good systems for boxing. Work with what they've got.
If you want to both, do both. Recognize that you are splitting your time between two not entirely compatible goals/skills, and accept it (I do).
Of course, that all assumes you've actually defined your goals before you started training. If you didn't...well, do so now. Otherwise, you're traveling along a road with no idea of where you're going, and you may discover that the road doesn't go where you thought it did.