It’s hard for a new developer with no marketing power to really generate a lot of income from Steam - there is an enormous amount of competition and it will bury you shortly after release. The best thing you can do is listen to the complaints and act on them; either improve the state of your game, or write it off and learn for the next one.
Piracy is unfortunately inevitable, you will simply have to accept it. It’s important to realise that the majority of people who have pirated your game were never going to be paying customers anyway, for whatever reasons they have. The best you can do in this regard is either ignore it, or to try and find a way to engage ‘freeloaders’ and turn those that you can into customers.