I can't act normal around White people due to fear, how do I get over this paranoia?

Try to remember that no group is a monolith and try to gradually place yourself in situations in which you limit your time around Whites. Like today, you could just said 'What's up", wait for a response and then move on. I don't minimize your experience, I am Black and have some similar experiences. However, I persevere and try to judge people individually and not lump them all together. Remember we are more alike than we are different. There is only one race-the human race.