The Interaction you can cope with will vary depending on the condition of your illness. When you are feeling a little low, you will feel more vunerable and will need to limit your exposure to others as much as is realistically possible. If you try to avoid people altogether it will affect day to day living especially your job. It also wont help prepare you for times in the future that you will have to interact. However, if you throw yourself into large groups when you are feeling low, you will only heighten the feelings you have and make yourself feel worse overall.
Basically, its a balance that you need to get used to. Medication can help if you are not already on it but It has a stigma to it taht you need to overcome. It can take the edge off and make things easier if the right dose and meds are prescribed and along with counciling, you can quickly learn where your limits are in these situations. When you start to feel threatened by an envirnonment you can make your excuses and leave as soon as circumstance allows.
I hope this helps.