Dreaming of 2 exes at once

Hey everyone :) it's 2 in the morning while I'm writing this but I felt I had to get some sort of answer from this dream I've just had-
Firstly I just want to note that I lost my dad to cancer in June of this year and I've been urging to dream of him since but I haven't dreamt of him yet
I even went through a phase that lasted about 3 weeks where I didn't dream at all
This dream is the closest I've come to dreaming of him so ill get on with it and you can tell me any thoughts you have on it :)
The dream starts I'm with an ex boyfriend, and we're walking down a road, the road is familiar -
It's our first date, everything is the same and we're walking to the cinema.
But we never make it to the cinema, the dream flashes and we're at my mum and dads house
We're in my old bedroom and were arguing like there's no tomorrow
( side note we were only together for 2 weeks, we never argued)
We're screaming away when all of a sudden I shout "I've just lost my dad to cancer" he shouts back "I knew your dad had cancer ages ago" (my dad only found out he had cancer 10 days before he died, what scares me is that I'm aware hes dead in the dream)
Anyway, the dream switches again, I'm back at college, I'm sat with my college friends at a computer and a different ex walks into the room, but he ignores me, he's flirting with my friend and they're together,
And then the college turns into my school, (my school had a top floor that was padlocked off, I don't know why)
But I'm entering this padlocked place, and it feels like a thousand people have died in this place,
(My dad worked at my school as a cleaner, was this a sign from him?)
The dream switches one last time
I'm standing, on a road
It's night time, there's not a soul around
When my ex from college appears, he's got dark hair, dark eyes but I can see him clearly looking down at me, and he utters the words
'It has always been you'
The words woke me up, I felt like he was actually in the room with me when he said it.
And that ends my dream, please feel free to give me your thoughts on it, I'm in total loss about this dream, how was I aware my dad was dead in a memory from before he died? What is this all about :( thanks for reading such a long post guys and have a good night from UK :)