Hello, I'd like to help you with your question.
It was very smart of you to see a doctor first. By ruling out any physical cause, you can focus on dealing with this issue through therapy.
It sounds like you had an intense episode of fear that triggered anxiety
for you. At the time the first reaction occurred, you had many stimulants in your body. That can trigger an anxiety/fear reaction. Once that happens, you begin to associate the reaction to the circumstances in which they occurred in. In this case for you, it was when your boyfriend was with you. Since then when you recreate similar situations where someone is standing close to you, it triggers an emotional response that causes the same symptoms. Think of it like being in a car accident. You come to associate fear with getting back into the car. You have to take it one step at a time in order to overcome the fear reaction and learn that you will be ok.
One of the first steps is to understand that what you have experienced can be resolved. Once you lose your fear of the reaction, you can start to control it more.
The next step is to work on breaking the association you have with someone standing close to you and the reaction you have. That starts through learning to relax. If you can relax yourself, you can learn that you are ok when someone stands close to you. When you feel yourself becoming anxious you can choose to use these techniques to help yourself relax. Here is a resource that can help you get started:
You can also ask your doctor for a mild medication to help you feel more relaxed. Ativan can help as can Valium. You can take them as needed rather than all the time, which helps when you are dealing with situations that cause you to feel anxious.
You may also want to work on anxiety in general. The more you know, the more tools you have to help yourself. Here are some resources to help you:
The Cognitive Behavioral Workbook for Anxiety: A Step-by-Step Program by William J. Knaus EdD and Jon Carlson PsyD EdD
Coping with Anxiety: 10 Simple Ways to Relieve Anxiety, Fear & Worry by Edmund J. Bourne and Lorna Garano
You may also want to talk to a therapist, even short term. The support can help you work through your anxiety. Just having someone to talk to as you recover can help a lot.
I hope this has helped you,