enough is enough vs right thing to do?

[happysadconfused]

Hello. First time posting here for me, have been a visitor and lurker for quite some time, you ladies are all so honest and helpful, and being a bit lost and confused right now, thought I might run this by you.
Situation is I've just left my partner of 15 years and taken our dc with me, who is three, and we are staying with my mum.
I feel happy and relieved some of the time, and I feel different now I've made the break, I feel like 'me' again. Although this 'break' feels very fragile, as if it's just pretend almost.
Background is: he's not abusive, and day to day I love him as a person and friend and my dc's father, but I have no desire for him as I feel slowly but surely it's been whittled down over the years by his 'darker' side. He can get very angry, and shout and get very loud. He has always had these episodes since we've been together, but I always used to sit them out, wait until he came out of the other side, then carry on as normal, til the next time. Since I have had our dc, something hads changed in me. I'm am more confident, I have more self worth, and each time it's happened since I've been a mum, I've felt myself getting more and more fed up and angry at him for it! Especially when it happens in front of dc, and I get told to piss/fuck off in front of dc too which makes it ten times worse. Over the last year or so, I've been having sex with him, if I've honest out of a sense of duty, not desire on my part, most of the time anyway, and he needs it to be happy. After the last but one 'dark episode' I left for a night, and came back to talk, but it's been even more difficult to feel intimate with him since then, I just don't want to, and this has caused the latest blow up, and I left yesterday. Haven't spoken to him since.
Now, as I said I feel relieved and confident sometimes, looking forward to being 'me' again, then I feel sick sometimes (like now), I feel sorry and sad for us and him too, I really don't want to hurt him, and I feel really bloody gutted about taking my dc away form their family and home and familiar life (preschool etc as we are 1/2 hour away) and worried the effect this will have on my baby who loves their 'home and family'.
Don't quite know what I'm looking for really. Does this sound like a good reason to change everyones lives for ever? Am I just confused and a bit depressed maybe, not thinking straight?
There are loads of other factors too, but here is the founder problem, for me anyway. I'm quite sure he would see things quite differently.
Bloody hell, didn't mean it to be so long. Started out not knowing what to write....

Firstly, I want to thank each of you for your advice, sorry I've not responded to you all, but my time online is limited, and often have to reply very quickly.
So, he came again yesterday, he's feeling really bad about our son not living in his home anymore, and he's missing having him there too. (obviously) But he can't afford to live elsewhere as I said. The visit went ok, he gave us both a hug when he went, and mentioned transferring payment of my mobile d.debit and my car insurance dd to our joint account, which is the account my tax credit goes into, the only income I have right now. I agreed to this. I felt a lot better last night, just a tad calmer about things.
He texts me today to tell me the the dates and the amounts of the ddebits, so it looks like he's done that already.
Does anybody know if I can claim income support without proof of maintanence. I really don't want to involve the CSA, and do it privately, but do I need proof of that before I can claim?
I spoke to him earlier and his attitude seems to have changed a bit today, I feel he thinks I'm going to try to rip him off, which is the last thing I want to do.

Seems what's really important to him may be coming to the fore?

TBH, I would set up a new individual account for you and have your ddebits taken out of that, instead of having your tax credits going into a joint account. (Redirect your tcs into the new account too obv) The less entangled you are with your H the better -- I would not be ok with becoming more tied up with him at this point, really, but seeking to actively disentangle. You don't want to be taken to the cleaners or have your dds stopped by him and have creditors hounding you, thus making you look like someone financially irresponsible.

Regarding visitation of your DS, I think it would be important to set up a schedule asap, not have an uncertain, whenever he feels like it set-up. This will be better for your DS and for you because everyone will know what to expect -- your DS's anxiety will be reduced once there's a routine, and you won't have your turf 'intruded upon' at unexpected times. Plus, there's a real psychological benefit for everyone concerned that accompanies the setting of boundaries of this sort.