Self-control, to me, is the most vital part of our lives in a number of different ways. Not only under negative emotional state, on the contrary, it is a significant help if we have powerful self-control even during the best of our moments. And yes, it is quite easier said than done, but I myself have experienced various stages of my life where my self-control was all over the place. Making all those wrong life decisions, not being able to analyse the real opportunity costs involved at almost every step of my life, unable to comprehend the situation rationally and logically - I certainly have been through all that. And I am sure most of us have.
The only thing that all this taught me was nothing but self-control. A specific situation or an event will give you 10 different ways to react and deal with it. At the end of the day, it is only up to us to choose the best way and face the calamity appropriately. Most of the times, overthinking about something will lead you towards depression. At almost 30, what I tell myself now whenever I am under distress, is that things are meant to happen. Life is nothing but a constant combination of good and bad days. There will be successes and failures within oneself. All we can do to face it in a better way is the fact that replace 'good and bad days' with 'good and learning experiences'. Replace 'successes and failures' with 'successes and decent tries to succeed'. That's what I have been doing lately, and trust me, this has given me a lot more self-control over myself and all the negative thoughts and emotions, compared to the person I was 5 or 10 years back.
For me, whenever I am in distress, I just told myself that this will soon to pass and that everything happens for a reason. We just need to focus on the positive side of the issue rather than worrying too much on its negative.
That is so true.. and I have been doing the same since the past few years of my life. Even if not under all circumstances or instances, at least I have managed to extract something meaningful during my worst moments as much as I possibly could. Have controlled my reaction, frustration, overthinking habit and most of all, the extent to which something can affect me emotionally... Not saying I have mastered in it, but yes, it has certainly worked! :)