Hey Pasara and Hollygo,
Recognizing that you have issues is the first step. There is no shame in admitting you need some kind of help. Secondly, seeing a mental health professional is mandatory. There are many medications that can help with this "thought" problem. When I recognize that I'm starting to have these irrational thoughts, I call my doctor and get a prescription of a medication called Risperdol. Taking it for a while makes all the irrational thoughts go away, then I stop taking it unless the need returns.
Having "suicidal or irrational thoughts" is not an uncommon thing, especially when you have a lot of stress in your life. If you mention these thoughts to other people, you are basically crying out for attention and reassurance that your life has value. Most people that do this RARELY actually want to die. This can also happen to people that are mourning the loss of a family member, friend, or even a pet. During these times, major depression may sink in, as is the case especially during special occasions or holidays. These people can't imagine going on without their loved one, but don't have the physical motivation to do themselves in. People can also outwardly express their distress through physical actions, like refusing to eat, take medication, or even by cutting or inflicting pain on themselves. Secretly, these people really want someone to intervene, to notice their cry for attention.
Other people that can have "suicidal thoughts" can be people that have to deal with chronic or severe pain. I get these kind of thoughts when I have an excruciating migraine. It's not that I want to die, but I have a strong urge, and physical sensation to slice my wrists open. The "suicidal thought" is more like the desire to open up a pressure valve, to divert the pain from my head. Rationally, I know that I have no desire to kill myself, and I recognize the thought is just that, a thought. I also know that if I give in to the thought, I could die, and that's not what I want. Thus, I don't act on the thought. They are tough to get rid of though.
The vast majority of truly "suicidal people" are seriously depressed, and very seldom voice their wish to die to others. They either seek out help for themselves, if they are strong enough, or if someone recognizes the symptoms and intervenes.
If nobody intervenes, they carefully prepare their affairs as not to be a burden on those left behind. These preparations can take quite a bit of time if the person is on the OCD side, not so long if they quickly become dispondent. During this period, people around them may be able to pick up on some signs, withdrawal from people, friends and/or family, or normal activities. They may change the kind of friends they hang around with, the way they dress, or the music that they listen to. They may clean out their physical possessions by giving sentimental items away. They may concetrate on getting their finances in order.
On another level, a person contemplating suicide may concentrate or obsess on how they are going to complete the task. This could be done by collecting pills, researching methods on the internet, taking an interest in chemistry, etc... There are even web sites dedicated solely to the subject of suicide.
Keeping close watch on these people is vital, and checking the history on any computers the person has access to my provide lifesaving clues.
I guess the bottom line is that we all have to be our brother's keeper. If you, or someone you know, is thinking about, showing signs of preparation for suicide, or even acting strangely, get professional help immediately. There is nothing worse than survivor guilt, especially if signs are there and get ignored.
Nothing is so bad it's worth dying over. Hang in there and let us know how you are doing.