Some threads that resonate well here. I am challenged with what the cognitive therapists call a "low frustration threshold". When things do not go quite right and frustration builds the step into a sense of failure is very close => and there lies the gateway to depression.

Add in a little judgement from the people around you and the journey to "acute stress-induced depression" is complete. This is a whole lot simpler than any other form of clinical depression because it is so totally coming out of your head. Your thoughts are creating the same chemical flows that trigger depression.

My path out of this had a few parts. 1. Get away from the sources of the stress. 2. Go easy on yourself when you get frustrated - find a distraction and have another go later. 3. Find 2 people to talk to every day - I used to go to the shops every day and talk to the check out clerk and the person behind me in the queue. Their smiles add value to your life. 4. Find a way to get positive chemical flows going - I use cycling; I use photography; I use orchid spotting. When someone likes a photo I have posted I feel good and the chemicals get smacked by friendly chemicals.