Hi LOW. I have been following this but not had anything to add to the brilliant advice the others have given you...but reading your post just now I was shouting at the telly so thought it was time to join in!
You say that the only bad thing was that they made you jealous? But that's not true, is it? The bad thing is that when you asked your H what was going on, he shouted at you, threatened you, threatened to take the kids and then stormed off leaving you alone wondering where he was and if he comes back.
From what I see, the issue here is not the texts (although it sounds fishy, some women put up with stuff like that and it's not for me to say) the issue is his behaviour towards you. He threatens you, he shouts (which the DCs WILL be listening to) he hurls verbal abuse at you at storms off like a grumpy teenager. THIS IS NOT NORMAL BEHAVIOUR. (Sorry, shouting again!).
Honestly. You are not living in a normal relationship with a normal person, having normal disagreements. You are living with a bully who shows you no respect, is constantly putting you down to the extent you think that its normal, and who is setting a HORRENDOUS example to your children as to how a man is.
I understand leaving is a huge issue, but PLEASE look into your options. Get some self esteem - the college course sounds fantastic! That, plus homestart or similar, will help you make friends - then you will get this horrible relationship in perspective and be strong enough to stand up to him. Otherwise in 30 years' time you could be watching your sons do this to their wives.....
Please. Re-read the thread from the start and look at what he has put you through - things he has said etc. Now imagine it's a friend telling you this about her - what would you say to her? Would you tell her it's OK? Didn't think so.