CMS payment reduction

I am wondering if anyone has ever had any success in getting CMS payment reductions, on the basis of when you met the person you were on a very low income, and 8 years later you are on a considerably higher income, this person has never worked, it seems unfair she is benefiting from my years of working myself into the ground.

Here’s my case: when I was 19 I was dating a girl, when I tried to leave her she tried to kill herself to make me stay (there’s a hospital record reflecting this).

I was young an naive and felt guilt so I stayed, she told me she was on the pill, she lied, then told me she was pregnant, quite late in the pregnancy- I had no say in this.

I stayed for about a year however having someone do that to you is hard, I eventually left, I have no relationship with the child.

When she had the baby I was on 18k a year, she has never worked a day in her life, and still doesn’t work, she also lives at home with her parents.

I am now 28, 29 this year, I have a base salary of 94k and I get extra with bonuses and RSU’s which takes me over 100k.

As I’m over 100k I’m being taxed 40%, I’ve lost my basic allowance and I’m paying £800 a month in CMS - this goes directly to her and not through CMS.

I’ve always paid from day one and always incremented the payments as soon as I’ve had a pay rise.

I’ve worked my back off to get to where I am in my career, grew up very poor and it’s not been easy to be honest.

My fiancée and I would like to have a child eventually but of course nursery is very expensive.

We life a modest house, in a 3 bed semi which we have a mortgage on, and do not live beyond our means. We’re not materialistic.

My finance and I would like to start a family of our own, we have no family to help us so the option is she goes back to work and we pay for nursery (we don’t get any free hours due to my salary) or she stays home and we take a huge pay cut with not much money left at the end of the month - we would struggle.

Has anyone had any success in getting a reduction? I’m not trying to totally stop payments but maybe £500 a month could be more reasonable, £800 is an extortionate amount and it seems unfair as when she met me I was very poor and now 8 years later after so much work she can benefit from my sacrifices to improve and better my life.

Would really appreciate any advice, it’s getting my finance down, from her POV she’s supported me through thick and thin, supported me grinding which took a huge toll on us both and our relationship, she’d love to be a stay at home mum with our kid until they go to school but we can’t afford that as I’m paying for someone else who has a kid in full time education and she’s never worked a day in her life.