Thanks for posting your query at DoctorSpring.com
I have gone through your question in detail and I can understand what you are going though.
From what you have stated it is quite clear that you are having an adjustment disorder. It can occur with regular stress and it can also occur biologically without any stress as well. There are various effective therapies for depression like fluoxetine, venlafaxine, bupropion, mirtazapine or escitalopram and they are all very effective and mostly safe. You may also require some benzodiazepines like clonazepam or lorazepam for a short period like 2-3 weeks to reduce the anxiety and help with your sleep.
If you are averse to the drug therapies then there is also an option of cognitive behavioural therapy. This therapy is taken by either a psychologist or a psychiatrist in which the therapist identifies impaired cognitions (Thoughts) and try to correct them. They are 15-20 min weekly session and there should be around 8-10 sessions to help you with your illness.
You may visit a psychiatrist initially and if the symptoms do not settle down then you may consider augmenting your treatment with the counselling as well.
Hope this helps,
In case if you have any further query, do let me know.
Dr. Srikanth Reddy