7 years of marriage and no intimacy

I've been married to my wife and mother of my children for 7 years. The intimacy and sex has really gone downhill within the last few years. It's at the point now, where I have to in a way force her to have sex. When I say force I mean talk her into it and persuade her into it. And if we do its only once a few weeks. When we first got to get her and married, we were crazy about each other and all over one another. Now there's now in Tammy, no affection and I have to fight for a kiss. She stays home with the kids, when I get home, it's instantly "about time you're home" nothing like hey how was your day.. I feel like I bend over backwards for her with work, coming home to make dinner 90 % of the time, dishes, playing with the kids then getting them to bed. Granted she is with the kids all day and what not which I totally understand and I know is not easy one bit. I don't think I could do that, so I give her huge kuddos for that and any stay at home mom for that matter. I just feel like we are so far off on pages from each other and it's really getting to me. On top of this, I know our kids see mom and dad not kissing, not touching, not holding hands and hugging. I don't want them growing up to be not affectionate towards their partner and I definitely want my daughters to know how a guy should treat a woman, so when they are older they don't date the dirt bags. Any advice and or comments is appreciated.