SO playing up?! HELP!!

*PLEASE HELP ME*
We're in an LDR. Two weeks ago, SO was suppose to come and see me but  the day before his supposed visit, my dad had an accident which resulted in me taking care of him. My SO then had to cancel on coming (he was furious but understood why I couldn't meet/see him...)
Two weeks has past and we've had literally planned last week for him to come but our schedules keep colliding  and we changed the dates again to this week...
Past 8pm I messaged him asking if he's not coming tomorrow because I know he's busy with work (him being a business man and everything!...can't do much but try and be patient with him as he has a lot of clients...)
It's nearly midnight now and he still hasn't replied....
I don't mind if he doesn't reply till tomorrow morning/afternoon....
I'm not a clingy type of girlfriend and I'm quite independent...so him not replying quick enough doesn't bother me
I just hoped he wouldn't put my hopes up and cancel everything last minute....
I'm planning to SUPRISE him for his birthday in November. I've never been to his city before and since I'm the type of girl to do things lone wolf style!...I'm literally planning and booking reservations on where to stay and what to do when I'm there....the city he leaves in is pretty old fashioned and I like it!! 
I'm 18 and he's 25 in November....I know our age gap is a bit far off...I hope he's not playing up :(
Am I overreacting girls??
I feel like he just doesn't want to come in general because last time he asked me if I can go to him instead and he would pay for my flight but I refused because;
1. I want to show him the city I live in
2. I can pay for my own flight if I wanted to go see him
3. My parents don't know I'm with him yet, thus why I won't go to his city without my parents permission...
My older sister has set me down and gave me the talk on this relationship and literally told me not to expect a lot and get my hopes up as she went through the same situation at the same age (18) dating someone the same age as my SO now....
I don't know what to do!! HELP!!! 
What do you girls think??
Please be honest with me!!