...I'm not sure if my husband has given up completely. At the moment it seems that we stand no chance of getting back from where we are, I want to try, not to save things but to build something we'd both be happy with but he's not sure if his feelings for me will ever come back.
....He's very angry, feels unloved, and is unable to imagine going forward at this point. He hasn't left, we have to small children (6 and 4) and he says he doesn't know how he'll feel in the future....
I think that SSMguy has given you some good suggestions.
MWD's book the Sex Starved Marriage has a number of good suggestions and reading it and asking your husband to read it and discuss it could help.
Another couple books I would suggest are Chapman's the Five Languages of Love. It is really important that you find out what your husbands languages of love are and that you do things that make him feel loved in "his" languages of love and not yours. That is if he needs acts of service to feel loved, perform acts of service. If he needs words of affirmation to feel loved, praish him for what he does well. If he needs touch, make sure he gets the touching he needs. If his primary language of love is gifts, give him ocasional and special gifts. If his primary language of love is quality time, make sure that even with small children that you spend some adult time with your husband talking and connecting emotionally.
Also, I would suggest that since you have a young family that you get yourself a subscription to Red Book Magazine. It is sort of like Cosmopolitan for the woman who has a husband and family and wants to keep them happy along with her own happiness. Even my 60-year old wife has come to enjoy that magazine when it arrives each month with ideas on relationships and combining the roles of mother/wife/homemaker/lover/independent person.
To help find the spark and rebuild your relationship you might also want to read John Gottmans the Seven Principals for Making Marriage Work. It has a lot of great ideas in it about what is both important in a relationship and how to not be destructive, as well as how to do things that bring couples together as opposed to doing things that add distance.
I am a big advocate of board certified sex theapists and if you are in a sex starved marriage because your husband has emotionally/physically withdrawn from you, they would be appropriate. Sex can be the glue that helps cement basically good relationships together. You might if in a "do it your self role," try asking him about some of the best sexual experiences that he has had with you and then try to recreate-relive some of them. It is a way of skipping over recent rejection to focus on a past closeness that may allow him to let go of the pain for a moment.
Sexual rejection (whether real or imagined) hurts at such a basic primal level. Actually "hurt" is much to mild a word. I can speak from personal experience, that it took me a long time (not as long as my wife) before I forgave her and before I was willing to expose myself to her being able to emotionally hurt me (through sexual rejection). If you are consistent in your love for your spouse, if they feel loved, and if they want to be in a loving relationship with you (which he once did and he has two children who need you as a couple, and you provide him with what he needs, he will probably fall in love with you once again, but on a deeper level.
Good luck to you.
>43 years of marriage--My wife and I are now closer than we have been in decades. I believe that my SSM is over.