Is it normal to feel very bad after feeling confidence and superpower

It sounds like a typical flatline. It can last from some hours to some months but it is rare to last so much. My longest flatline was like 2-3 weeks.

 

I've had this same experience. It's normal. We're consciously taking control of the way the pendulum has been swinging back and forth between pleasure and pain. Old habits die hard. While you're body and mind are establishing a new homeostatic baseline in response to balanced hormones and new lifestyle habits, you will fluctuate between extremes while adjusting to your new normal. The roller coaster will level out as you continue along your journey. Stay strong.

 

You know that you can't feel like a superman forever. Don't you?
That energy won't last forever' and there will be a time when you reach the flatline where you feel neither good not bad.
One thing that you can do is doing things that you like the most. Maybe coding, cooking, working out, playing, you know what I mean. These activities will make you so happy and proud of yourself. Just don't make masturbation a part of it for god sake