In a facebook group of Stoics, someone posted a questions about what they should do if their practice of Stoicism was being perceived as cold-heartedness. I’ll include an expanded version of my reply here.
My knee-jerk reaction is that your practice of Stoicism shouldn’t negatively effect those around you. Stoicism, to me, isn’t a total repudiation of emotions, esp. not sympathy and care for your fellow man.
Emotions, feelings, physical reactions can mitigated, but not eliminated. Nor would it be desirable for them to be so. To me, it is not letting your emotions and whims control you. Within the two spheres of influence, what we can control and what we cannot, one of the things we cannot perfectly control is having a human central nervous system, an endocrine system, etc. You cannot, and should not seek to, banish all emotions from you, least of all sympathy to the pain of your brothers and sisters.
First you might ask “Am I being cold-hearted? Am I doing something wrong?” If so, correct that error. If in fact, you are doing something that does not represent your highest and best good, virtue: you should want to change that. If you are causing undue or immoral harm, you should want to reduce that.
Secondly, if you are not in the wrong, you cannot control how another perceives your actions. You might attempt to educate or teach them about what you’re doing. You might talk about healthy thinking and unhealthy thinking. If the person can receive that message, of course.
Seneca talks about grief in Letter LXIII. I think it’s reasonable to see if that applies to other emotions.
Helping a friend or lover bear some pain would be virtuous, to my mind.