Even though you are feeling guilty about giving the boys to their father they seem happy and content with him and you did what you thought was best for your boys, make sure you don't make them feel guilty about your current husband not liking them that will make them resent you and feel like you chose your husband over them. Tell them that boys should be with their father so that they can learn to be men this way you can still have a special relationship with them even though they do not live with you. Anyone that doesn't have children and has never had them will not have patience for them because they don't know what they are getting into and even when they do have children around they still do not know the true meaning of being a parent and taking the good with the bad plus the fact that your current husband saw his parents act the same way with children, he doesn't know anything else. It's good that you both went to counseling to get your marriage back on track but I think your current husband needed parenting class much more and it would still be helpful to help him deal with your boys when they are with you.
The boys are going to miss you but just like with any other marriage that breaks up or divorces they have to live separate from their parents and only see them every once in while this situation is no different maybe you could try calling them every day and let them know you were thinking about them and wanted them to know how much you love them as long as they know and feel that they are loved they will be fine, they are now at the age where they need a father figure and a man to show them the way. Don't be so hard on yourself you did what you felt you had to do for everyone involved.
I didn't think I had enough room to mention that when we married he had three kids from a previous marriage and for a few years we had all 5 children. His kids are all older and have since left home. He favored his kids but says he was strict and impatient with them when they were young (like mine were).
Now that his are gone (and I helped raise them) he says he is tired of the parenting thing and just wants me and he wants everything to be as stress free as possible. I really would like to finish raising at least one of my boys. My husband is not very good with either of them but much harder on my firstborn who has a learning disability.
If you haven't talked to your husband about your wishes then you need to communicate this to him and if he truly loves you he will accept your children too, you may have to give him an ultimatum either he accept one of your boys coming back or you are going to have to leave and take care of your child who needs you more than he could since he is an adult. Maybe suggest parenting classes for him before you choose which son you want but that is a touchy subject because then your other son will wonder why you took one and not both and you don't want hurt feelings and to split the boys up may be traumatizing to have to live separate from each other if they are use to living together. You will have to think long and hard about this decision because it could hurt alot of people in the process so make sure that the boys are okay with living separate and if they are not then it may be best to keep them together. Also if your current husband isn't willing to accept you children then he doesn't accept you because you are a package deal. Tell him you will no longer accept his treatment of your children and he has to show them the same respect he tries to show you and if he cannot do that then you may have to rethink your position in the marriage and your future with this man.