CS1105 instructor is nuts

I’m done w this dude he’s either high or wants me to fail in his class. I follow the rubric exactly, cite my sources and go above n beyond the requirements. It’s been 2 weeks and he keeps giving me a low grade without any feedback except "good job on the assignment" bs. emailed him the same day and he gave a vague response like "improvements needed". I let it slide but he did the exact same thing again and provided no feedback. I’m convinced some of these "instructors" were marked poorly and they’re only doing it for revenge. I’ve emailed him again, let’s see what happens but I’m also considering taking this forward. What do you guys think?