@mummy917
I agree with others, the negative feelings you have are feelings he's instilled in you over the years. But those feelings will lessen with the passing of time. I think more therapy is a good idea.
As far as maintenance, why do you feel you have to speak with him about it? You know that conversation isn't going to go well no matter how you approach it. Let your solicitor handle that for you. Or just file with CMS. You owe him no warning. He didn't give you any, did he? Just keep documenting his time with the DC and file when the time is right.
And I also agree that he is miles ahead of you, emotionally and logistically, on this journey. You're playing 'catch up' and unfortunately the emotional catch up really can't be rushed. It'll happen, probably just not as quickly as you want it to. So don't kick yourself for telling him you miss him. It's the truth. But acknowledge that the 'him' you miss is not and was never the 'him' he really was. You miss the 'him' that was 'good times', not the one that manipulated and, yes, controlled you. But latter one is the real him, not Mr Good Times.
As far as handovers, if your Mum or Dad won't do it do you think it might help if the handovers took place in a public location, like a coffee shop or park? Or would your parents or a friend simple be there with you for handovers? Sometimes just a presence gives us strength and a better ability to not say things we really don't want to say. Personally, if I were your mum I'd do handovers simply so I could fix a death-ray stare on him along with cat's bum mouth. I would be 'icily polite' but radiate my hatred like the heat of a volcano. I'd take care the DC didn't notice, but he sure would!!
Listen, you're doing really, really well! Don't let a little 'blip' on your radar discombobulate you.