Hi, Having trouble with concentration and crowding of thoughts are the two sides of one coin. I would suggest you to go for your
Vitamin B12 and D3 testing. It does happen some times if the vitamins are low then mood is also gloomy and dejected feeling.
Next Steps
Please follow up after tests we can evaluate accordingly.
Health Tips
Dont jump on any diagnosis at this stage. Dont believe on feelings. Get it confirm and then we can work it out.