Anyone I know who has been bereaved by suicide has never really recovered from it.
Most of torture themselves wouldn't why they didn't see it coming, what the person thought it was the only option, what signs they missed, what they could have done differently etc.
I'm sorry you are feeling depressed and that it is making you consider suicide. I do know a lot of people who have been suicidal and/or depressed. Some have recovered extremely well, others have their depression under control aided by either counselling, medication or lifestyle changes or a combination.
There is help out there and you won't always feel this way. Please talk to someone, anyone but preferably a GP or counsellor.
My cousin died from suicide and we would have done anything possible to prevent if it we could have done. We know there were a lot of difficulties & challenges in his life at the time, marraige breakdown, job loss, alcohol abuse but with support he would have been able to overcome them. You need support. You need someone to hear you and help you. Don't try deal with it alone. Depression can be an all consuming bitch but it won't always be like that.
What support to do you? How can people here help? Do you need family support? Financial guidance etc. If you want to share some of the things that are tough at the moment, people can help give you contact numbers etc. that they have found helpful.
Talk to someone now please.