The only person who can give a diagnosis of whether your wife is bipolar or not is her Dr. What you have described is not a healthy relationship. Separation is for the purpose of working on the marriage not for prolonged control of one partner over the other. You have to decide what you are going to do independent of what your wife does or doesn't do. You cannot make her get help or decide to work on your marriage. I highly recommend the book
Love Must Be Tough: New Hope for Marriages in Crisis by Dr. James Dobson. It will give you very specific steps to take. My thoughts and prayers are with you. Blessings!
M go Blue!