This isn't nice to hear I know but... It's good that the relationship ended because it was incredibly unhealthy.
Can you see that it's unhealthy to consider a relationship of a matter of weeks as an all consuming thing that's the only part of someone's life they enjoy?
You have built this up in your head to more than it was, even by saying things like 'half a month' later you fell in love too. That's two weeks. You dated him for 8 weeks, it's no time at all and shouldn't be taking up so much headspace.
I don't say this to be cruel but to try and help you see how this fixation on the relationship is not healthy.
And you say he said this:
maybe leave things where that are before it gets deeper for both of us, as he's in love with me too but he's scared he's going to ruin this and end up hurting me, said I'm too special to get involved in how he feels and to find someone I deserve. After trying to talk him round and saying I would support him he thought it best to block me and try and concentrate on his mental health. He states he is making this decision to benefit me aswell as himself. He said he is absolutely heartbroken to let me go and will miss me. He was actually very tearful and even had to leave work.
He told you he wanted to break up. Instead of respecting that, you kept trying to talk him round even knowing that he was struggling and felt depressed and under pressure. You should have respected he wanted to end it rather than adding more pressure or making him feel guilty, to the point he wants to block you as he knows you're unlikely to let him go and respect that it's over.
It sounds like he's really having a tough time and is mature enough to know that he isn't in the right headspace for a relationship. He's been kind and honest and you need to accept his decision as nobody owes anybody a relationship.
I'm sure you're a lovely person but you do sound very naive asking things like what is the chance of him changing his mind - well nobody could possibly answer that accurately because everyone is individual and there's no set equation to it.
This was an 8ish week relationship - I think before you start dating anyone again it would be great for you to do some work on your boundaries and expectations so that you don't fall into the pattern of too much, too soon / mutual lovebombing again.
Try to let this one go, you barely know each other and you need to focus on you 