Hi, I'd like to help you with your question.
Setting boundaries with this man is a good way to get him to leave you alone. Decide what you feel your boundaries should be. For example, if he approaches you with something personal, mention to him that you are busy. Be polite but firm. And do not show emotion such as irritation or anger. This only tells him that he can affect you anytime he wants. Repeat your message as necessary. If he inquires whether or not he has offended you, say No, I'm just busy. Say that to any of his attempts to reach you emotionally.
As long as you stick to your point, he should get the message.
To handle your emotions, realize what is making you upset. Is it his behavior, your fear that he will stalk you, or something else? Once you identify why you are feeing upset and angry, then you will be able to respond to it. Most likely, part of it is because this man's behavior makes you feel out of control over your own space that contributes to your feelings. When someone invades our personal space, it can cause anxiety because we feel the need to defend ourselves. With this man always in your space, you are most likely feeling overwhelmed.
As you notice yourself becoming upset, take a deep breath. This will help you focus. Using the response we talked about above will help you feel more grounded and in control. Focus on repeating your message calmly and firmly. This gives you a measure of control over the situation. You no longer have to worry about how to respond to him. You already have a response no matter what he says.
If you can, schedule a walk or time out of the office during the day. This will help you take a break and give you the space you need from this man.
Are you allowed to keep desk toys at work? There are many helpful toys to let you work out your stress and anxiety over this situation.
Also, keep track of any behavior this man has that bothers you. Keep a journal in your handbag (it may get seen if you leave it in your desk). Jot down dates, times and what happened in the journal. Then if you need to take the situation back to the manager, you have proof of what happened. You also will not have to rely on memory.
If you feel the situation gets more out of control and you cannot relax at work, consider talking to a counselor. You could use the support to get you through.
I hope this has helped you,