Help Budgeting please

Hi, this is my first post here so I hope i don't break any rules.

I 25M and I have Autism and I've never been good with money. I'm posting here because I have nowhere else left to go.

I live in the UK but I'm from Australia, I moved here in 2019 and since then I've been on the poverty line consistently barely getting by. I have a fulltime job that I started in November but due to poor mental health and Long COVID causing chronic fatigue I've basically been unable to work more than part time hours for the last 2 year's and it's left me destitute if that's the right word. I am in debt of excess of $25000 AUD to my mum, and currently I'm over my £500 overdraft by about £2 due to the bus fee.

Due to being a new starter at my job I've been on probation and I've spent the majority of my first 5 months off sick, which has meant my sick pay has been incredibly low. 3 of my 4 paychecks were less than the cost of my rent. I only pay £625 in rent plus bills, and if I were working fulltime I'd get around £1600 a month. Last month I got a normal paycheck for the first time in what's felt like years but I managed to spend every last penny and I'm so frustrated at myself and scared because I'm here on sponsorship and my probation ends at the end of May and there's a good chance my work will decide I'm actually unfit to work full time and I don't know what I'm gonna do if that happens!! I can't afford to get back home and I've bled my mum dry. I don't want to leave or find a new job as any kind of big changes take months for me to adapt to due to my autism. I'm just struggling so much and it feels like nobody cares like I don't have any friends I can really talk to this about.

I don't know what else to say but I won't get paid until the 24th and I don't know how I'll survive until then, or survive after if they fire me. I'm out of options and I'm really scared about what that means for me because I've spent a good deal of the last year almost clinically insane and suicidal and I'm finally doing better but it feels like everything is about to be pulled out from under me.

I'm just after any advice anyone can offer or even just a friendly person to talk to. I don't know what else to do