Sorry, this is probably been too late, but I just saw your message.
Ok, what he has done. Based on the facts you have told us, not what we might speculate re OW, so this is the minimum he has done:
He has been deceitful while living with you, avoided being honest with you and not given your marriage a chance by being emotionally unavailable and unkind to you. Cowardly and unpleasant.
He has walked out, not even bothering to explain, at a time when your DD are most vulnerable. Very very selfish and disrespectful.
He has left it to you to talk to your daughters and expects you to fix things with them for him. Cowardly.
He has tried to interfere with your right to privacy and not given you space, texting, the books, the sodding guinea pig and the bloody garage. Controlling and selfish and very disrespectful.
He has stolen your holiday (IMO the very least he could have done is let you go on it with a friend). Selfish
He is keeping you short of money, making life very difficult for you, then trying to buy your daughters affection. Controlling, mean and selfish.
So from those brief examples, deceitful, selfish, controlling and cowardly, with a dose of meanness and poverty of spirit on the side. No wonder your sister thinks you are better off without him.
That's just what I can think of off the top of my head, I am sure if I reread your posts, I could think of more - will that do for a start?
I know it's hard, but its best you don't speak to him as I don't think anything he said would make you feel better and most probably worse.