Prepare yourself for him NOT being a great dad once he leaves, that came as a shock to me (he currently hasn't seen her for over 3 years and hasn't spoken to her since Christmas).
Get all your legal/financial stuff in order.
Why is he not leaving? Is the property in his name also?
I couldn't do the shagging someone else straight away but accept it helps some.
Keep as healthy as possible as that supports your mental/emotional strength too.
Let uni know, there's usually loads of support available that's not well known about - as you work for a bank they could be very helpful on organising the financial side of things.
Once he's left get rid of everything that upsets you, or at least hide away (eg I did this with wedding album, video etc, I wanted to keep for my daughter but too much to have to look at regularly in the early days.
Have someone you can rant at (sounds like you do in bff hope that stays the case). Invaluable support!
Most controversial piece of advice I'm going to give is -
While it's advisable not to bad mouth ex to your dc, that DOESN'T Mean you have to defend him if he's being a shit dad either.
That's the mistake I made 'daddy does love you he's just not good at showing it' 'I'm sure theres a good reason daddy didnt call when he promised he would/is late for contact' etc it dismisses the child's feelings and makes them think they're wrong to feel they've been treated unfairly, plus they'll rail at you for lying to them.
Good luck 
