For such a depressing thread i can kind of relate to. It has some of the most beautiful wallpapers i've ever seen.
I didn't get the number of the OP but on the subject of Suicide, therapists, and everything.
Therapists will help, those who stop to listen of course. Psychologists too might help, even tho most of what they will do is talk to you trying to solve your problem through that.
Therapists will analyze your behavior and problem and when they know what it is they will give you remedies and medication. So that your brain gets more chemical balance. You have probably some type of depression. One of the more severe cases which makes you stop and think so vastly that you lose alls hope. Happiness is nothing more than chemicals telling you you feel good, to learn to be happy you have to first talk to a professional, because you have a severe chemical imbalance it seems.
Try not to kill yourself or end things, there's cures for you. Just have to find it, Anxiety exercises and talking with professionals might lead you to the right path. I hope you see the light ans get happier and healthier down the line.