welcome to Healthcare Magic.
From your history, many of the symptoms are suggestive of depression
. In depression head scan usually come normal. Depression usually occur neuro transmitters imbalance in brain, primarily involving serotonin, due to that medical treatment is effective in treatment of depression. For that you can consult nearby psychiatrist
in cold may be due to thyroid
hormone problem, so also get your thyroid function test done. Thyroid problem also increases chances of developing depression.
Wish you all the best.
Dr Ashish Kumar Mittal