I have too. I used to suffer from severe depression when I was a teenager, I understand what it's like to be suicidal. However, I am a Christian and thankfully, God has gotten me through that dark period.
There are some things that we can do to change our circumstances and one is to start finding things to be thankful for. Another is to learn to forgive others when they wrong you, talk about a freeing experience, and change your diet. Get off the refined flour, sugar, high carbs add in some protein and good fats and in a matter of days the depression starts to lift.
I speak from experience. It's not always easy, but it is possible.