Advice from a retired qualified mental nurse. Hope it helps? The tin opener is the negative outlet for your frustration. You are 'catastrophizing' this is a common disorder associated with depression and anxiety. Things get blown out of all proportion. Try to tell yourself this when you have these kind of thoughts and take back control over your thinking. It may sound silly but speak out loud and say to yourself 'This is one of my irrational thoughts it will not rule my life!' Try it the next time you feel things are overwhelming you.
You need a healthy outlet for your anger and mood. Make a new year resolution to exercise more. Even just a twenty minute daily walk. Make the effort to see people socially. You don't have to be the life and soul of the party but a little social contact will help significantly. If you drink alcohol either stop, or cut down, This is a depressant and will exacerbate you symptoms all the more. Try to have a regular sleep pattern, the exercise should help this. People underestimate the importance of sleep on our mental health.
It won't be easy and tell yourself this rather than beat yourself up! Try to stop when you say to yourself 'I should do this' or I should be like that' or 'I must be this, or that' The words 'should' and 'must' only add more pressure. This is called 'Musterbation' think of that word and laugh to yourself if you find yourself using those words. One day at a time. An old Chinese proverb: 'A thousand mile journey begins with the first step' so remind yourself of that. New year, new start.
Good luck!