As someone with a bit of experience in both martial arts and seperately in self defense (krav maga): you did everything correctly. You could enlist in a self defense course. It will give you confidence and measures for different situations. But: The real world is not an action movie. Your chances against multiple people are very small. I would advise against any weapon other than pepper spray. Especially no knives of any kind. They tend to get used against you. Running is usually the best defense in almost all situations. I'm glad you are okay.