Sadly, not every kid gets the parents they need or deserve. I don’t know what’s going on with your parents, but it sounds like they are both trying to erase their former life. You and your older brother represent the life they have left behind. It isn’t fair. It isn’t good. In my opinion, it isn’t moral. But I’m afraid there is little you can do to change it.
The only ray of good news in your story is that you and your brother are on the edge of adulthood. At 17 years old plus, the two of you have the opportunity to get jobs or further your education. At least for now, your parents are providing a place to live and some funds. Use that as a launch pad. The best response to your parents’ desertion that I can think of is for the two of you to create successful adult lives and demonstrate to them how wrong they were to separate from you.
In the meantime, I hope the two of you will actively search for interested and helpful older adult mentors. They can’t take the place of loving parents but they can give you friendship, advice, support and even love. Teachers and older people at your workplace are good candidates for that role. You may also have relatives in the extended family who sympathize with your situation and who would be willing to provide you with some guidance.
Your parents are like a dry well. It doesn’t matter how often you go to draw love, there isn’t enough there to bring up the buckets you need. To keep going to that dry well will only make you sadder and madder. Better to find a new source.
I wish you well,