Why did he come to the UK? I know you said the was a dispute and he felt unsafe but as PP have also asked, why didn't he move to somewhere else in Pakistan? It would kind of be a bit like us moving from London to Leeds. Why did he move to the UK when he had no money and no job? Also, why didn't he sort his visa out years ago?
Your whole relationship sounds dodgy, again as PP have pointed out. He was financially dependent on his friends for 4-5 years and then when they were probably getting fed up of him scrounging off them, he suddenly finds you to take over.
It doesn't sound like a normal relationship. If he had no money, I'm guessing you never really dated him. The relationship has never been equal.
He's using you and relying on your health issues that make you vulnerable. You're in a very vulnerable position and need to find support for yourself and detach from him.
You say you're struggling but just about managing to work. If you didn't have another adult to clothe, house and feed, you might be able to look at reducing your work hours.
If the relationship is genuine, he'd go back to Pakistan himself, get a job, and find a legal way to come to the UK. In fact, that's what he'd have done years ago.
There's no way I could get in a relationship and expect the man to financially support me for years! He's a scrounger. He's taking the piss out of you and all of the other people from abroad who have worked hard to come to the UK legally.