I wanted to feel differently inside, have any of you done that, how?
Maximum I've done it. I fell into it because for various reasons I couldn't work on the outside stuff any more. So, several things...
First, everything that you've achieved with the outside stuff isn't nothing, it counts. It's a huge achievement considering how emotionally damaged you seem to be. So you should to celebrate that even if it feels forced and unnatural, literally give yourself some kind of treat as acknowledgement of what you've achieved so far, you deserve it. That's step one of being kind to yourself. It might feel weird now but being kind to yourself gets easier to do over time.
Second, the process you applied with all the outside stuff, it's the same process for the inside stuff. Make a list of what you need (with a therapist's help if necessary), things like peace, somewhere that feels like home, safety etc. and take baby steps to achieve it.
Third, you do have a starting place for "you", the rage. You've got all your "civilized situations" personas, but the inside isn't totally empty, there's rage and that comes from the true you. You sound like a pressurised container about to explode, so maybe you need to do something drastic like taking a week off work, renting a rage room for a few hours and setting up daily therapy appointments for the rest of the week so you can put yourself back together enough to return to work.
You should probably consider yourself "ill" at the moment, even if you don't feel that's correct, because it'll give you a framework to exist within. So if you had eg glandular fever for 6 months, you wouldn't be trying to carry on as normal. You'd be getting signed off work if necessary, and when you do go to work you'd be coming home and taking it easy as much as possible. You wouldn't be seeing anyone who causes you stress because it'd hamper your recovery. You'd be doing activities you find soothing and that don't tire you out too much. As well as eating healthy, drinking water and getting plenty of sleep. So treat yourself as if you're ill and maybe you'll be able to calm down a bit, through showing yourself the kindness of giving yourself a break and a chance to recover from the all-consuming rage. Literally tell people you're not well and you don't have the energy for socialising right now, or you need a break from them and the arguing with them, or whatever. You don't have to invent an illness you can just say you don't want to talk about it. Your health is your personal business, it's fine not to discuss it with anyone if you don't want to. Cut anything pressurised or stressful to a minimum and add in peaceful things.
When the rage has died down a bit, you can try to look at what other aspects of you there are inside. You've buried yourself and built personas because you needed to to survive, but you're still in there.
As for which good things make life worth it, that comes down to experimenting. You don't know who you are yet (apart from angry) so you need to discover what you like and don't like. It's a big world, something in it will make you smile in your soul, you just have to find what and it might take time and failed experiments to do so.
You might also benefit from both medication and regular therapy, at least until you've stopped feeling like you're going to explode. You sound depressed to me, feeling empty, joyless and all that.
my husband is cruel and scapegoats me himself as he knows he can
I want out of the marriage and he threatened to destroy me
Beloved I'm going to guess this could be the reason for your strained relationship with DD and your friends distancing themselves.
DD I'm guessing has suffered some type of childhood abuse and neglect from having you two as parents. Looks like she doesn't trust you to keep DGD safe, hence the supervised visits. When your DD sees you're away from your husband perhaps you'll be able to build a better relationship with her.
Your friends I'm wondering if they're fair-weather friends and have backed away because maybe you've been (understandably) venting about your husband a bit? For a start I'd join some kind of social group or hobby that's in another town where hopefully people don't know your mum or husband. It's no use trying to be deep friends with people who thinks your mum and husband are lovely because they don't see the bad side of them.