The cops are unlikely to help you, wherever you are.
Instead, try social services, or a domestic abuse charity, they will be significantly more sympathetic and could potentially offer you support, or at least tools to try and deal with this situation.
The other thing is to protect yourself, go no contact or at least reduce it. It sounds from your short post that you are an adult and live in your own property - don’t let him in. If he has a key - change the locks. If he tries to break in then the police might help, try and gather as much evidence as you can (like a camera doorbell or other recording). Don’t answer any of his communication, if you can, block/delete him from all of your devices and social media. Personally, I would apply the same to your mother, that’s up to you, but it sounds like she’s at the very least enabling him, so isn’t looking out for your best interests, and you need to ask yourself if those are the kind of people you want in your life.
Life is too short to hang on to toxic people who harm us in the hope that they might change. Being related doesn’t make them worthy of your time energy or love. If they do eventually regret their actions and want to apologise and try to make amends, you can let them, or you can choose not to, both are valid.