I don’t think you are slow at getting started to understand but of course ‘knowing the right thing to do’ is easier than ‘doing the right thing’. I am a believer though that once you begin to read the addiction it is easier to spot the ‘clues’ and asking for £5 is one such clue. He knew if he asked for too much he wouldn’t get it so he went for a small amount hoping the door would open just enough to get his foot in – after all it worked before! His addiction is looking for chinks in your armour – he is aware you are getting stronger so he is adopting the more seductive approach – and you didn’t fall for it – well done.
It is a minefield at the beginning but look how well you did – because you didn’t pick up the phone and blast him, he couldn’t inflict more hurt, so you recovered quicker – ‘you’ were in control. The healing that gives you deep down positive feelings takes time – it is gradual and exhausting but ultimately it is a walk back to life.
You are right that his behaviour is ridiculous and selfish but it should never be underestimated – it is dangerous and you are doing the right thing in shielding your daughter. I know you are holding back because of his addiction and not seeking to punish him but he will not believe that – it won’t suit him to believe it – he needs to blame you. He has the capability to be a good father, when he controls his life but at the moment he is out of control.
Telling him you love him will not have made matters worse – he maybe thought the enablement door was open again but you have scotched that thought; so if he does any deep thinking at all he can hear that you love him but you will not pander to his addiction – I can’t think of a better message.
Keep going as you are and keep seeing your friends. In my opinion, unless his mother tells you that she doesn’t want to speak to you, it is a good line to keep open especially as she is your daughter’s grandmother. The adults can all ‘move on’ (as he puts it) without you losing touch with his mother.
Everything you have written says that you are doing well.