Hi
i understand your concern.
I appreciate that you have given very nice history.
I had gone through it and guess it may like you have
depression.
According to DSM 5 depression has require following features for at least 2 weeks.
Low mood or sad mood with loss of interest in daily activities.
Change in apatite or change in weight.
sleep disturbance.
somatic complains like lack of concentration/easily getting
fatigue etc.
It is psychological process and need proper evaluation.
Early treatment will bring fast and better recovery.
It can be treated with different modalities of treatment like medicines and counseling. In medicines SSRI/escitalopram/
sertraline can be useful. but take psychiatrist advise before taking any medicines.
Sudden change in mood and thinking may require assessment. so
consult psychiatrist and get help.
Thank you.
Wish you a very good health.