Well, I don't remember of EVER being happy for more than a minute or two, but, before high school, I was bullied, I felt depressed and disgusted by myself, but, strangely, not really suicidal... With time I went somehow numb, I suppressed all of my emotions...
When I went to high school (so, I was 14 then), the bullying stopped, my emotions returned, but I felt alone and helpless and I started thinking about suicide, since then, for the last 5 years, there were probably no more than 20 days when I didn't think about suicide...
But untill 5-6 months ago I could suppress suicidal thoughts, my naive hopes of a happier life were still there, but a few things broke me, and now I think of suicide, seriously, all days...