From the age of 18, I suffered from pretty appalling headaches and turned to alternative medicine, having had little help from my GP. Four years ago, during pregnancy, I developed Horner's syndrome (a drooping eyelid), so when Caitlin was six weeks old I had a brain scan. It showed a very large shadow in the centre of my head. A biopsy revealed that it was an adeno-cystic carcinoma - in plain English, a big tumour in the middle of my head.
The surgeon said he couldn't operate because it was "in tiger country". I was in complete shock for two days. I later had an operation to "de- bulk" the tumour, followed by an intensive course of radiotherapy and chemotherapy.
For two years I had no symptoms and we hoped it had gone away. I had a fantastic time. I discovered photography, and was really grateful for my brush with death for having shown me how precious life was.
But in December I lost all feeling in half of my face. I had another scan and was given the new prognosis. Knowing that nothing can be done at least saves me from the painful cycle of hope and despair.
I do, in a way, feel apologetic to Tim, for him having fallen in love with someone who is going to cause him pain. I love him more than my own life. We were so sure of each other that he proposed two days after our first kiss, and we were married three months later. I said to him that it was too perfect, and that something would ruin it, as in the film Love Story.
I feel it's harder for him than for me because he's going to have to pick up the pieces. We talk about everything, but I do shield him from some things. I've already made all the arrangements for the funeral - I'm having a hearse drawn by four horses with black plumes on their heads.
I would like Tim eventually to meet someone else, because I want him to be happy. But I find it difficult imagining someone else being a mother to Caitlin. I trust him to choose someone who will love her.
I've written a lot of letters to him and to Caitlin to read when I'm gone, telling them how much I love them. I've written one for Caitlin to open on her wedding day.
I thought about writing one for each of her birthdays, but I didn't want the ghost of a dead woman appearing at every family function.
I do get upset when she talks about when she's a big girl, as I won't be there. If I think about it too much I cry. But I try not to - the less upset I am, the more fun things we can do together and the more good memories she will have.
I reckon I've got about six months left of doing "mum" stuff with her. I don't want her to remember me as someone ill in bed. I want her to remember the three of us dancing in the kitchen. I have more fun than you would think for a girl who's dying.
She knows I have cancer - I said it was something in my head that the doctor couldn't get out. We give her lots of opportunities to talk about it. I haven't explicitly talked about dying.
I started up the website - called Shadow in Tiger Country, a Diary of Terminal Cancer - because I wanted to write a book and have a photographic exhibition, and it was the quickest way to get my work seen. I also saw it as therapy.
It's got a personal diary about what I've been doing and how I'm feeling, and a gallery of photographs, and Tim has his own page. I get messages from people all over the world saying how much it helps them.
Even people who don't have cancer have said it's put their life into perspective. It's made me feel that there's a purpose for the illness. Being able to help so many people and influence their lives for the better makes me feel that I'm winning. Whether I live or die I've put the cancer to use, and I'm not a victim of it.
When we were first told about the cancer I nearly passed out. It was almost impossible to comprehend - it still is. I've never thought "Why me?" - or, more importantly, "Why Louise?" It's just life. Some people get it, some people don't.
The main thing I feel is sadness. Sadness for all the time we could have had together, the fact that she will never see Caitlin grow up, and that Caitlin will never really know what a fantastic mother she is.
I'm scared of life without Louise. We're each a half, and together we make up a whole. To have found such a love and then for it to be taken away is devastating. Louise makes things easier for me with her honesty, and having to look after Caitlin means that you can't break down. I've now more or less stopped working, in order to look after her and spend as much time with Louise as possible.
I worry that when I'm on my own, I'll make mistakes with Caitlin's life. The thought of her being motherless is one of the few things that can really bring me to tears. It's the saddest thing. At least, by the time it all finishes, I will have had about 10 years with Louise.
One of the things I will miss is the laughter. Since the moment we met, we have laughed, no matter what the circumstances.
Some people think it's weird that we joke about the cancer, but it's our way of getting through it. I'll miss Louise's body as well - the sex, the caresses, the kisses.
Half her face has recently gone numb and lost all feeling. When I kiss it, she can't feel it. I hate thinking that bits of her are already gone from me. I can't imagine having a relationship with anyone else, but I suppose I will because I'm only 28. But there's the terrible thing that I would always be comparing her to Louise, and everyone else would be a compromise.
If I allowed myself to get upset, I would cry and cry and cry and never stop. I don't want to waste the time I have. You can spend your whole life becoming obsessed with it and becoming a victim of it.
I understand it's healthy to cry and express it, but there's time for that later. Our whole marriage has always been fun and exciting, and I wouldn't want anything to change that.