Spousal/child maintenance

[user1469838185]

Hi I am new so please be gentle with me. I am going to court for maintenance soon and wonder if anyone can help me.
Brief history: Married for 20 years, he is with someone else with no children. He takes home 600 a week, she could work but chooses not to so he pays her way, result he can't afford to pay me anything! I am on my own with an autistic son of 18, I suffered a small stroke 3 years ago and had a double carotid artery op. I am 61 so basically I am unlikely to meet anyone or get a job as I am my sons full time carer. I have no family to help or any real friends (I also have 5 rescue dogs which were 'ours'). I get 209 a weeks carers, my son gets 193 disability allowance. I pay full rent of 120 a week as my landlord does not accept rent allowance.
I don't mind not having more a life as I love my son but I don't want to be poor for the rest of my life. The question is, they say the two of you can come to some agreement just before you go in to see the judge. But if I go too high and he says no, the judge might go lower. If I accept a lower figure the judge might have gone higher, what do you think? ps I forgot to add I gave up a career to care for my son, I was training to be an accountant.

[Mamabear3017]

Can't help with the other bits but legally your landlord can't stop you claiming housing benefit, it's not his business where the rent comes from.