No, most men are not murderers and will not just kill you. People like your father and brother are exceptions in how they behave. There are kind people out there who would never do a thing like that.
In some cases, people who are like your father or brother might feel that you are traumatised and used to that behaviour. So, if you encounter anyone acting like them, leave immediately. Kind people might feel not as familiar, but there are many of them and they might even help or protect you.
I feel for you. You deserve kindness and care. It is a good thing that you are a kind person and that you remained like that even with all you have been through. I hope you find an environment with people who are also like that where you can heal.
The way your family is, is not normal. And the way your life is right now, is not what life should be. And this is not your fault, but it is because of the environment you are in. And this can change.
Maybe you can get help from a domestic violence protection organisation to make sure you have a way to get away safely.

I don't know. This is the first time in my life I have ever heard about people smelling ants. I have a really good sense of smell normally, but I have never smelled ants. Never heard anybody say they could smell them either. So, I think it might be quite common.