Adding on,.what we're talking about here is emotional regulation. This isn't the same as controlling emotions, nor doing away with them. More like managing the volume so you can actually listen to them.
You could even take out the word emotion and simply talk about self-regulation. @PostalDude if that's the case, it's not just whether you've tried meditation or therapy. On top of sticking to them because it can take time, the type of therapy matters. DBT is a specific modality which offers a lot of tools for self-regulation. This doesn't mean dispensing with other approaches; but it's a good place to start. Person-centered therapies might be subsequently useful and perhaps EMDR if you suspect a trauma element (just some examples. Not prescriptive).
From there understanding the effects of culture is good and so is looking at (real) Stoicism. But the latter is almost a later stage step, in that you want to be in the right frame of mind to properly apprehend it.