You are not wrong to feel hurt and neglected. But, he is not wrong to be focusing on the activities of his trip.
He's on your mind all day, and you're wondering what he's doing and how much he's enjoying this birthday trip. However, it would be very unusual for a man to have his wife on his mind so much in this situation for three reasons:
1. He's a MAN.
They tend to compartmentalize things, and focus on one thing at a time. Literally. Women's brains think about multiple things at the same time and we often CAN'T stop thoughts of our husbands and children from mixing in with all of the others. Think of a man's brain like a waffle: there are multiple little boxes with walls between them. Each box represents a different thing in his life. He has a box labeled "football game", and others labeled "buy beer", "wife", "kids", "work", "call home", and believe it or not, there's even one that's labeled "nothing". It is not possible for him to be in more than one of these boxes at a time. Think of a woman's brain as a bowl of spaghetti, and each noodle represents one aspect of her life. The noodles are all jumbled together, so each one intersects with many other noodles. We have a hard time ignoring the thoughts that pop to the surface from all of the other aspects of our lives that one strand touches. The "husband" and "children" strands are extra long and thick.
2. He's busy enjoying the trip.
He has fun things to do, or he's relaxing in his "nothing" box from the demanding, tiring work and commute he's been doing. You are home with the same old drudgery.
3. He has already had contact with you several times in one day, so most men would check off the "call home" box for the day.
Given that you're feeling a lack of affection and caring from him in general, it's natural for you to feel the way that you do. You're probably also stressed with the demands of being home with three small children, and having your husband unavailable and/or unwilling to pinch hit for you.
What I'm about to suggest is going to seem counter-intuitive and will be very hard for you to do at first, but it is the best way to get your husband to act loving to you.
1. Work on being an ideal wife. NOT because he deserves it or because you're doing anything wrong now. Do it because you will know that you have given it your very best shot and you will know that you have become blameless in contributing to the rift in your marriage.
2. Keep ALL of your communication with him POSITIVE. No man wants to be told by his wife to avoid drinking too much because he'll be drinking the next day. He can figure that out for himself and make his own choice. Men are extra sensitive to criticism and anything that he can interpret as trying to control him. Instead, find other things to say in your messages, such as listening to game and texting him about a great play, or tell him something cute that one of the kids did.
3. Make it clear to him that you strongly desire him in bed (even if you are feeling too hurt to want him at first). Send one teasing message a night when he's away about what sexy thing you're going to do to him the first night he gets home. (Don't bombard him; leave him desiring more of you, not wishing you'd back off.) Find the energy somehow on the nights when he's home to make him glad that you're his woman. Put on make-up and brush your hair before he gets home.
4. Give him a big payoff every time he does any tiny thing to help with the house or kids. Lots of praise, compliment what a great dad he is or how well junior does at bedtime when Dad reads the story, etc. Don't be fake, but make it worth his while to do more. (Yes, I know that he SHOULD be doing these things as the dad anyway, but he ISN'T, and people aren't motivated by being criticized.) Let him do it HIS way, even if it isn't as good. Give him some companionship time after wards, with a casual mention that "since the kids are down to bed a little early, you have some time to sit with him". Whatever you do, don't ever respond with a complaint or long list of everything else he should do, such as "If you'd do that more often, I could have more time to do the other things you want me to do."
5. Find a way to get some stress relief for yourself. Call friends when you need to talk (men usually don't like to talk as much as we do, so find another way to meet some of this need for yourself). Get a babysitter once in awhile so that you can go do something on your own with friends or just shop alone. Trade off babysitting with another mother if you can't afford it. It would be great if your husband would give you a night or two a month when he looks after the kids, but he seems awfully stretched to the limit already. When I was a stay at home M., I tried to have a lot of my "girl time" at lunches, afternoon movies, or ladies' meetings during the day, so that it didn't infringe upon family time when my husband was home. But, it's also good for dads to be alone with the kids for the evening sometimes and get to do things in their own style on their own. Finding some social outlets and stress relief for yourself will take the pressure off of your husband to be responsible for all of your womanly need to talk and connect with adults and will help you to be your best self.
The bottom line is to become a source of pleasure, encouragement, and relaxation for your husband, so that you and your home will be his haven. He still probably won't be able to think in the "call home" box at the same time that he's busy with something else, but he sure will look forward to getting back home with you! And, then you have the best chance of getting the affection and caring that you need and deserve.