i assume that you are asking the question will they hate you if you give them to him? im sorry but i think they will. i also think you will feel far worse without them, and not only will your other kids suffer because they have an extremely miserable mummy, but they will also miss out on their siblings.
i know you dont think you are depressed, but have you considered ads for stress? they dont turn you into a different person, they just help you cope with life a bit better. i have had them a couple of times (both when xp was being particularly awful) and they really did help. dont make your mind up against getting help, even if you only do it as a last resort. if you can cope without thats great, but before deciding anything about the kids, try them and see if you feel differently (because i am pretty sure you will).
my kids also enjoy going to their dads. they eat junk food til it comes out of their ears and stay up til all hours of the night playing computer games and watching 18 cert films (they are 5 and 6). at home they have to eat healthily most of the time, computer and tv time is limited and they are in bed before 8pm. and when they have stayed with him for a week, they are very glad to come home. kids need stability. holidays are lovely, but they need to know they are safe and looked after. parents look after children, friends dont and my x wants to be their friend.
it sounds like your dh is being supportive of you keeping the kids. would he deal with your x? for me it took a couple of weeks of not seeing mine to get him out of my system and gain some perspective on what was happening. you are not just deciding about this week or next month. if you hand your kids over to him now there is a very good chance you will never have them live with you again. will they grow up to be the people you want them to be if they live with him? do you really think you will feel you did the right thing in 20 years?
i really feel for you cos i remember just how heartbreaking a situation it can be when you feel you have no way out other than this. but i have been through court and me and the kids are so much happier now. the thought that i nearly lost ds1 to my x makes me feel sick. i really hope you can find some other way around this for the sake of you and all your children