Diminishing Interest

[trolls' bane]

I have one serious problem with my writing. When I start something, the first few pages are always great, as Lotesse pointed out on the first 6 chapters of ZAQ1 . Later on in the story, I slow down in writing it, going from four pages to two pages to half a page a day. The reason for this? It is not because I am losing interest (the title of the thread is misleading), it is because I am killing my character's appeal to others by beginning to add useless bits of conversation, over-charactering myslef--a major problem with me, since I am terrible at making up names, pointless remarks, poor interludes, over-describing and over-explaining, little plot progress, little story telling, using too many paranthasies, too little figurative speech, too many similies and metaphors which are always (and for worse) used to describe and tend to be vague (the chair was like a smoke tree in size), longer and longer sentences, and finally too much repitition in form:

Originally Posted by ZAQ1--Chapter?: Aldebaran

"I don't know," Siggy said. "I've never heard of such a creature!"
The Captain looked up from the map before him. "Sure! They are like elephants, in fact they are elephants. The first explorers from Earth brought elephants along with them because they could carry large loads and are relatively cheap. Here, they are so large because of the low gravity, which has allowed them to grow to such size. On an Earth like planet, they would simply be to heavy to get up."
"Oh." Siggy said. "I wondered because this Elephant here looks like it could tear down a Sequoia tree like a toothpick.
"I'm surprised you know what a Sequoia is," the Captain said.
"Of course I do," Siggy replied.

You see? It's terrible. THe longer the story, the worse I get. I plan too little and predict too much, if you get what I mean. We can all assume how the story will end up (if you have read it). I have little doubt in my mind that it will end with the protagonist (Sigmund) the victor, or at least with success. All stories end this way, unless you're George Orwell. I want to avoid such a monotoneous outcome, yet doubt it possible. I read my own writing, and instantly I don't feel like writing anymore. I guarentee you that I will end up leaving this story in a drawer, leaving the website abandoned, and forget about it for a few months. I already feel this happening, since I am thinking too much. I write as though I'm the character. With minimal planning, I just figure it out as I go. The problem is when I start to ramble on about something that has nothing to do with what is happening, or rambling on too much about what is happening. It gets real annoying for even me to read. As of now, ZAQ1 is far behind on where it should be, the parabola of writing is now beginning to go where I don't want it to go: below zero which means writer's block and/or abandoning.

Can someone help? Does anyone else have problems like this?