I'm not going to say video games are a waste of time, as I am not one to judge what people find important to them, but coming from a place where video games have been a serious hindrance to my progression in life (and still are), I can see where your stepdad is coming from. Although it sounds like he's dealing with it in a very mean-spirited manner, which never helps.
Sounds like you and your mom ought to find a way to move somewhere permanently away from your stepdad in any event.
Aside from that, all I can say is good luck with your situation and I hope you find a way to make it better sooner rather than later!
I cannot stress enough the importance of the last part. Surround yourself with people who lift you up, encourage you, and give you a good kick in the
when necessary.
It is definitely very difficult to pull yourself out of a deep pit but hanging around people who do nothing but motivate you to push forward is one of the best things you can do for yourself..