Try doing a full day's memory for 30 days before going to bed.
If the situation does not change in a month, see your doctor.
It's better not to joke with the brain
If you don't remember what happened yesterday, then it makes sense to see a doctor. This can be a symptom of a number of serious medical conditions. The sooner the doctor diagnoses and begins treatment, the more chances to slow down and the more prevent the development of the disease.
Try to still remember, reflect on what could have been yesterday. Large brains. About what time we got up. What did they do next: breakfast, computer, trips, meeting with someone, etc. It is better to write down on paper those actions that were immediately remembered. Then add between them what I still managed to remember.
Remember in the evening what happened during the day. What do you want to do tomorrow? Check which one you remember by morning. It works very well as a summary of the day and helps plan a new day.
To test the general ability of the mind for degradation, take a high school algebra / geometry / physics / chemistry textbook. Try to solve the simplest problems. Do you remember at least some formulas or terms? Do you understand what is needed and why?
Learning a foreign language as an adult helps reduce the risk of developing Alzheimer's disease, multiple sclerosis, etc.