What is death… What occurs after it happens.

Complex question.

First let us first talk only about the physical side of it. Many causes can lead to death, you may die suddenly (car crash, deadly stroke etc), or it might be a very long process taking hours or even days (for example the end of a long ilness when you drift in and out of consciousness for days in a hospital).

But the main thing is at the end you will lose consciousness never to regain it. If you ever had a medical operation that required anesthesia you will have an idea what I mean. This should really be seen in a positive light - whatever fear, pain etc might have led up to this will be gone. Physically-wise that's how it ends for you. What happens to your remains is a problem for the state or your family, it won't be of concern to you.

If you do not believe in any form of a spiritual life after death, then what I described in the paragrah above will be all that you will get to experience as far as death goes. Loss of consciousness and never regaining it.

Now, if you do believe that there is some spiritual life after death, then here is where things can take drasticaly different turns. Philosophers, Theologians, Holy Men and Mystics have ben arguing about this since the dawn of civilization.

So as far as spirituality goes, you need to find an expert authority person of your religion and talk this over. This is a common theme for people to ask priests, rabbis, mullahs and other religious figures. Any figure of authority within your religion (if he has a good head on his shoulders that is, dumb people can be found in any job) will be familiar with the topic and will provide you with all necessary information as far as that religion goes.

You mentioned "eternal loneliness". This is how hell is described in "High Church Catholicism" (as opposed to folk-belief-catholicism where you would instead have fire, brimstone, tar and devils with horns).
That is one possibility as far as catholicism goes. There are two other ones:

Heaven, which "High Church Catholicism" will describe as being with God and participating in God. As God is the absolute entirety of creation (and more) this means that you will get to participate in everything and anything you like. The church will stress that it is a fulfilling, voluntary experience that takes place out of time itself. I'm sorry if I oversimplified it a bit, Theologians tend to describe in in whole tomes, I wanted just a few sentences.

The third option is a transitory state nown as "Purgatory". This is a plae where you prepare, train and become purified so that you may go to heaven once you are ready. This is just a transitory place, as the ultimately everyone in purgatory will at some point become ready and go to Heaven. Old time Catholicism used to say that purgatory is a place of suffering (folk-catholicism sometimes still tends to do it), but modern "High Church Catholicism" will say that it is not necessarily the case. That this is more like athletes training for the olympics - it may be tiring or hard at times, but it is not torture in any way and it is all for an ultmate good goal.

That's how it works in Catholicism. For other religions, you need to talk with their own experts. I'm no priest, but I believe I'm well enough versed in the doctrine to offer this insight.

When you die, if you get buried your body will rot and the atoms that make up your body will be spread throughout the ground. Plants will eventually take up the atoms that made your body in the form of nutrients and the atoms will then form part of the plant structure. Maybe that plant will get eaten by an animal like a sheep or cow and your atoms will be passed onto it. Then that animal might be eaten by a person and your atoms end up being used by their body until they too, die, and the atoms that make up their body will be spread throughout the ground...
I'm not spiritual so I don't think we have an eternal conscience/soul. When you die your conscience goes too, this life is all we have so be happy and make others happy.

I hope this wasn't too morbid.

*Kinda Spiritual.. my personal understanding*A soul/spirit is limitless and infinite. It can achieve anything, it is the creator! Since it’s the limitless creator it has no boundaries. It can’t experience feelings like regret, depression, struggle, making efforts to achieve something and other stuff. So we are born; as a human being, in this physical world. The purpose is to gain experiences, the purpose is to ‘live’ a life bound by the beautiful laws of physics, caring about others, learning as you grow up! All of it ! Joys and sorrows, all of them are experiences. We are here to experience ! To explore the planet with our limited timid human bodies. We are here to endure. To learn! All of it is for the nurturing of the soul! What say?! (I hope I don’t sound like a paranoid :P )So well death is the end of a conscious self of ours.. we aren't our physical self! Our human life is like a single leaf of a giant tree which can be referred to as our higher consciousness! When we die that leaf falls, though the life experiences are fed back to the tree and a new leaf grows.

Ok, let me add my two cents ( I am a Pastor). If you believe in Jesus (from your vague description it sounds as though you are Christian--forgive me if this is too big an assumption). The one thing about that is the fear of death has been removed because, in the end, the price has been paid and heaven awaits. If eternal loneliness is your description of hell (actually not a bad description because of being separated from God) then you need not fear it. Keep it in mind only as a thought because Jesus saved you from it. Remember, "Therefore there is no condemnation to those who are in Christ Jesus." Jesus gives you the strength to face this fear head on. "There is no fear in love, but perfect love casts out fear". Fear is given to us as a protection ( the old fight or flight ), but dwelling on it does you no good. Instead, concentrate on that perfect Love. List all the things in your life that you are thankful for. Praise God and then open your heart and tell Him how you feel. Yes, He knows already. But, and this is key, He still wants to hear from you. Forget the Thees and Thous. Talk to Him from the heart just like you would your best friend. Blessings to you.