As long as you can deal with yourself, and your situation, good for you. Just as long as you're not going to drive yourself crazy then you don't have to talk to anyone. You are right, you don't owe anyone anything, just focus on doing things that will makes the rest of your life easier to deal with. If you think your old instructor's going to go away quietly, leave 'em be. If not, you may want to reconsider talking to him. You haven't been treated right, so from here on out, it's all about YOU!