confused on weather to leave my 6 year marriage..

Hi,

Iv been married for 6 years (got married at 19) we have 2 preschoolers together and work together also.
When we first got together he was controlling but i saw past that he loved him for his personaility of being a spirit of the moment person and the rebel he was at the time.
We have our fights just like any other couple but he gets jealous very easily and we end up in a agurement just because i was talking with a male friend at a party. He has female friends and i dont get jealous because i trust him. but he doesnt trust me and iv done nothing for him not to trust me. We have both only ever slept with one person(each other) so true sweethearts as u would say. We broke up for a few days when we were younger but then he wouldnt leave me alone and he said he couldnt live without me and that he was gonna kill himself so out of pity i got back with him..

But the last 2 years have been not the greatest with more fighting/aguring infront of the kids. He is always going out with his friends while i stay at home with the kids but yet if i wanted to go out by myself with friends he would make it an issue, therefore i dont go out with friends.
And if he doesnt get his way he throws a bit tantrum like a 3yo. He makes everything all my fault and when i try to agure he turns it all round as he always likes to be right and unfortunally hes good at debating and can find an excuse for anything in 1 sec flat. He puts me down and tells me im dizzy and pathetic and called me lots of other things i have low self-estem because of him and his words and yes i have told him all this before LOTS but as usual he turns it around and trys to tell me that i need help!! He gets all angry over the littlest things and starts screaming at me. He puts our kids down at times too which really bugs me!!
Im scared that if i leave he'll make my life a living hell and he has already said he would.

Iv tryed to leave before but he wont let me leave without the kids and when he leaves the house he takes my car so i cant leave. He then waits for me to cool down and talks me around to staying ALWAYS!!!
I dont know how much more i can take but yet something is keeping me..yes i still love my husband but the conflict is just too much and he wont see a councillor.
My friends still cant believe im with him, they say he treats me like !**@!..rings me up abusing me while im at there place and tells me to get back home.
Iv thought about going to see a councillor myself without him.

I really dont know what to do or how to do anything.
Please Help