I only have a few suggestions. IDK what would work for you, but those are surface level stuff.
How is your breath? You could try to do some breathing exercises. Learn a new breathing technique and just focus on that. Tell yourself that you are going to take this time to learn, and that the rest of the world can wait for just these few moments. Just focus on your breath, and then when thoughts come, just breathe. Refocus yourself on your breath after you notice the thoughts.
Take note of your body. Feel the stress and tension in the muscles. Feel how tightly you hold your jaw, and relax it. Just do it. Part by part, piece by piece. Focus on relaxation and breathing.
It sounds like these intrusive thoughts and combination of stress are really hanging on your mind, and you know what? That is OK. Just go back to the basics and stop putting so much pressure on yourself to preform when doing meditation. Just remember what you are feeling is temporary, and will pass.
There are some days where I just can’t meditate at all.
On those days I decide to shift my focus. I might do another round of standing qi gong or just go through the Eight Movements for some time. Something that is meditation-like, but not quite the traditional view of “ok sit on the pillow”.
It might help you to write down your thoughts and pressing matters before you start a meditation session.
You could practice trying to ‘Be the Observer’ and try to get an alternative perspective on your situation based on the practice.
You could try to meditate with a candle in front of you. Watch the flame and watch your breath. Then when a thought goes into your head, send it into the fire of the candle and watch it burn so that it does not distract you for too long in your meditation. You can worry about it later. Right now its you, your breath, and the cleansing fire.
You could take the candle meditation further, to breathing in the flames energy and see the energy filling you, burning through all the gunk and dispelling the chains you put around yourself. It could help give you energy and insight to deal with the situations at work.