Is it true that Stoics repress their emotions and feelings?
No. This is an old misunderstanding. Emotions and feelings are normal and natural, and sometimes they're even essential to our survival. There are times when being afraid and running away is the wisest course of action. Where the misunderstanding comes from is the Stoic belief that emotions are based upon a judgment.
All of us, including Stoics, have emotional reactions to events that can cause anger, grief, and fear, but after the initial instinctive reaction, it is our judgment about the event that either inflames or cools the emotion. As Shakespeare said in Hamlet, “There is nothing either good or bad, but thinking makes it so.” Shakespeare was a student of Stoic philosophy, by the way, and he often used Stoic themes in his plays.
We believe it is our judgment that makes something either good or bad, not the thing in itself. If we are unhappy, then it was some judgment that inflamed the emotions and made us unhappy. Happiness is everyone's desire, and Stoicism is all about increasing your happiness and living well.
No no just as @amorfati says its a huge misunderstanding that stoics are logical emotionless individual that pursue a rational based robotic world view. But that is totally wrong stoics are more close to rational naturalists that work to chase after natural greatness and happiness. As emotions are an intrinsic.part of human nature so to be devoid of emotions is nothing but a pained state of self.