I'm sorry to hear you've been going through a rough time - it's never easy. There are different types of depression and different treatments. Have you been seen by a psychiatrist yet? It may be a good idea, even to just get a consult. It's hard to answer your question, we can't diagnose here, but it's obvious you have some sort of depression. Usually if a depression lasts more then a couple of months, it's called clinical depression, which means it isn't situational and you may need meds. Many folks function very well on anti-depressants and can lead very productive lives. Have a more indepth chat with your doc and ask a lot of questions - being more informed will help you work on getting well.
What you describe is a typical period of us carrying too much for too long and eventually breaking down. Once we do break down we feel worthless,weak, and all those negative things when the reality is that break is telling us something has to change, and quickly.
It manifests as depression and you know the symptoms as you've felt them. They are many and varied and the longer left untreated the stronger they get.
Depression does not normally heal itself at all. Once you have it it is you who needs to work hard under treatment to reverse the process. There is no "normal" time for healing a case of depression as we are all different.
The keys though to a recovery are fairly well known. They include firstly acknowledging you have the illness and accept it for what it is, an illness and not a punishment from God or anywhere else. It is just an illness, albeit a very serious one which can be life threatening.
Then you need to have good support which means a good doc, therapist and family/friends who will help you get through the worst times.
Above all though it is you who needs to make the changes to your life that will relieve the pressure that caused the depression. In your case it would seem logical to suggest you do not continue in that job where the problem started. Staying there would seem to have inevitable results as, despite the best will in the world the employer will slowly pile the pressure back on to you as you again cope. You know this so a job change is the major priority based on what you have told us.
You will identify these things that need changing best through discussion with a therapist so you can talk through any problems that cause you grief, stress and sadden you. It may be you don't exercise, sleep badly and keep late hours, maybe drink and many other things which can be identified as being a part of the problem.
I do agree that a psychiatrist is always best for depression treatment but I don't agree that meds are always needed. They may be short term but try the therapist route first please.
In regards to "clinical depression" I'm sorry but I must disagree with what was written earlier. Clinical depression is simply a term which means a case of depression being treated by a clinician, a doctor. So we all have clinical depression once treated. If untreated then it is not clinical depression as no clinician is involved.
Clinical depression is not a type of depression although is is commonly misconceived as such. It is a term many docs use as they don't want to explain any further usually because they can't identify to a lower level than just "depression". Too many patients are misled into thinking it is a unique type but it is not.
The 2 months mentioned also has nothing to do with clinical depression and it is not necessarily situational or genetic. These two statements are incorrect and not useful here. Sorry LCC.
I've had depression 48 years now and mine is situational, or environmental as it is better known. Being caused by events during my life. About 1/3rd of cases may be genetic but there are no studies that prove this beyond doubt.
Your answers are to face the illness, learn about it and seek appropriate treatment from a doc you like and trust. Then work together with a therapist to identify the issues and try to fix them.