You're right, that's a low dose and it sounds like you are not really in serious need of it. You are off the K2 which was causing it. Have you checked your BP since? If it's not very high, I doubt that you coming off it would even be the cause of any chest tightness or lightheadedness. I think you are better off without it.
That said, I agree, it is best to consult with a doctor before changing your meds. But I suspect he/she would agree with me.