I'm quite sure that I'm depressed and I can't help but feel completely embarred...?

You have nothing to be embarred about! Depression is a serious medical condition that is outside the control of the individual. Depression is not always caused by particular events or cirstances and can be brought on for no reason at all. If you have had these negative emotions for so long you should definitley speak to your GP about your symptoms. There is a type of depression called dysthymia which is a mood disorder where people may feel mildly depressed on most days over a period of at least two years - the symptoms resemble major depression, but with less severity. More information can be found on http://www.depression-anxiety-stress-test.org along with a free online test for depression.