The cleaner is a luxury I've never had. Not a necessity so that would be gone from my budget. At the very least, could you cut from weekly to fortnightly or once a month? But that feels like an easy £280.
The £100 for pocket money and activities for your child - how much is pocket money and how much is for the activities? I feel like these are two separate budget lines really, one you have control over and the other not so much. Do you receive Child Benefit?
The £110 on phones is a lot, when are the contracts up? I'd definitely look at a cheaper option for your son especially. I hate negotiating phone contracts.
The medical bills is a huge one too. I can see that it's not NHS and it's for PTSD, this I would make a priority to source via the NHS as it sounds like your personal financial situation has changed and paying out of pocket for this therapy is no longer affordable for you.
Most of us also don't have a holiday home but I've not gone straight to selling that as I wonder if that's actually a useful source of fairly passive income for you? Do you rent it out regularly? So you offset the costs with some income.
I can see you've already mentioned the need to address spend on food. Try seeing what you can do for a couple of months. Planning meals helps, batch cooking and freezing portioned meals helps, having a food food budget and reducing waste. No eating out, no take aways, making sure you use all leftovers. Does your son get free school meals? They came in the year after my youngest left primary so I've always had to pay for their dinners but that would make a huge difference to my food budget, well over £1k a year.
Pet insurance is tough. Ours is fairly high for our surviving dog. My parents don't have pet insurance because they can cover the costs if they come up, we can't. I see someone else suggested saving instead of using the insurance. If it's £100 a month that sounds like an option. You could save it instead of paying the insurance and have £1200 in a year then have that £100 back in your budget. Or cut saving to £50 and keep that budget line in there for longer but have £50 more wriggle room immediately. It's a gamble though.
Have a look on the Martin Lewis site for every single approach to looking at all of your utility bills.
Loan repayments, I assume these were agreed to when you had a higher income. Can you contact all of these about negotiating a lower monthly payment? You'll probably end up paying more over time but it'll give you the breathing space you need on a monthly basis.
What's the interest like on the repayments? Are you able to get a 0% credit card to move some things around, still maintain repayments but cut back that interest? I know it'll depend on lots of things but that's helped me to juggle card repayments in the past and get on top of things again.
Within your general living costs, I see you mention holidays. Have you changed the type of holiday you go on? We don't go abroad every year. Clothes wise too, are you using vinted to sell and buy? You've probably done all of this but just in case.
As Micawber says in David Copperfield: "Annual income twenty pounds, annual expenditure nineteen nineteen and six, result happiness. Annual income twenty pounds, annual expenditure twenty pounds ought and six, result misery." - you've got to get that monthly balance right or things will spiral. Well done for asking for help, it's hard.