Oh my. My first reaction after reading your letter was, “This poor, poor person. Her self-esteem is so low she has become a bully.” Only people with very low self-esteem constantly measure themselves against others in a way that makes them feel superior. Only those with terrible self-esteem carry this much need to pull attention to themselves in any way, even very negative ways.
Overt bullies act up and act out. Your nit-picking or messing with your partner’s games are good examples. A covert bully is someone who does this secretly in ways that others aren’t aware of. An example of this is when you stopped caring about a student once he chose you over another teacher. Feeling small, you manipulate others and pump up your ego to feel big. As you are finding out every day, these tactics don’t really work. You still feel empty and without positive relationships.
You need far more help than I can give you in an advice column. If you really want to get better and feel better, I urge you to see a mental health counselor. Take your letter and this response with you to jump start your sessions. Really. Please give yourself the gift of some treatment to set your life on a different and much, much happier path.
I wish you well.