I have suffered from depression since I was 16, it's deeply unpleasant. In 2007 something strange happened to me. Following a particularly enjoyable event I started to feel uncontrollably euphoric this feeling lasted for 7 days I could barely sleep and started to write at a mammoth pace.
Immediately my doctor referred me to a psychiatrist who diagnosed me with bipolar. Now we all have good days and bad but bipolar disorder is like the most extreme version of this imaginable. I know take mood stabilisers to balance my mood but the most effective thing I have found to help me is talking therapy. Alas in the UK funding for these services are at a very low ebb meaning that talking therapy is rare thing. Another helpful tool is a mood diary in which you write down your mood state and comment on your daily activities. This allows you to identify triggers that may cause a mood swing. A combination of these therapies do make a difference however when you have a condition like this it will reoccur. The best to view bipolar is to realise it is an illness and you aren't crazy, millions of people have the disorder, sometimes it can deeply affect ability to function but it is not the sufferers fault.