You need to get checked out asap to your GP for ful blood work including paraproteins just in case.
Give full history incl the aneamia.
I’m doing case studies like this in Heamatology & Clinical chemistry units at uni…ironic?
Could be fatigue, consumption or production probs red blood cells, aging or millions of things-who really knows.
You’re unwell, it’s been a few days, you have a history of blood disorder which your Gp should have followed up.
The answer is get checked up and don’t go home with a blood test. Then when you get the results, ask for a diagnosis please-nobody ever does.
Also ask for the lab results, make sure it has full blood count, iron levels and immune cell count and endocrines checked if this is ok.
The best thing yo can do is go with a detailed history to your go-it shows you have done some work and you will get better care.
Good luck.