Breh, you can't innately not show sympathy/empathy, you're not a sociopath, if you were you wouldn't be making this thread, and also I can tell you're not, trust me on that. So that's out of the way, you're not a psycho/sociopath whatever.
You're just angry, frustrated and emotionally numb. From a young age you've gone through a lot so your brains natural means of protecting you was to 'shut off' and now being 'shut off' is your default feeling. The vodka is also a 'downer' so your brain is constantly quite a 'dark' place.
Now, right now, it's not like you can't show sympathy, it's that you can't show ANY emotion, big difference, you don't allow yourself to get too angry, too excited, too anything and empathy and sympathy are just two things, right now you're not allowing yourself to show anything.
Breh, you're in a bit of a hard place at the moment, so how you are is perfectly normal, you are a black man who has to experience the racism that most black people experience but unlike other black people you didn't have the parents to help you cope, you have a white mother who God bless her, can't teach you how to be a black man. Your black father who could have been the person to teach you those things wasn't a consistent present figure. You are growing up in a racist white world which is built to work against you with little support.
The 'system' isn't something that works for you, you haven't liked education and you don't like typical work. So you're at a place where by you see the things you want (girls, cars, money, blah blah) but you don't have the resources to get them. You're broke, you want money but you don't fit the mold of the people that the 'normal world' allows to get money.
Why you feel so numb is common sense, you've been through a lot and you're trying your best to get through.
What you must focus on how is how to allow this to work for you, or snap out of it.