You mention siblings when talking about your childhood but not in your current life. Do you have siblings? Do you have relationships with them? Do they have children? I'm just confused as you mention your parents, grandmother and cousins but not siblings, nieces or nephews.
Anyway...I offer the following trying to be helpful and not sanctimonious (sometimes tone doesn't come across in writing and really, I feel for you). Your childhood memories are not your children's - they have their own memories and probably feel surrounded by as much love as you did, even though it looks different from what you remember. Growing up, I had no cousins or grandparents on my mom's side of the family. Her parents had died, her brothers were bachelors and her sister was married without children. We saw them on Easter, Thanksgiving, Christmas and every few years on special occasions like a baptism or First Communion. They never baby-sat or came over just because. I delivered by aunt's eulogy this past Monday and my memories of her were that she was, in fact, always there for us. Even if it was just 3 times a year, it felt pretty consistent and loving to us. I remember her presence more than any sense of absence. My siblings and I had plenty of companionship among each other. We do have 11 cousins on my father's side but there is 30 years between the oldest and youngest so it's not as if we all grew up together.
Even now, my oldest children didn't have any first cousins until they were 10. We see one sister's two young children maybe once or twice a year, and my other sister did move back here recently so we see more of her and my niece but for the first two years of her life, we saw her once. My husband's brother has no children. And yet, they don't feel deprived of anything and our holidays are full of joy and love. There really doesn't seem to be anything lacking here.
So...is there something else going on that's making you feel some sense of emptiness? You mention not feeling needed - why does need equate to love in your head? Why can't the fact that they enjoy your company and invite you back every year be enough? Is it possible that you have seasonal depression or do you feel this empty about your family other times of the year as well?
I'm a member of flylady.net and one of the big things in that group is getting organized for the holidays. One of the steps is to ask your spouse and kids what their favorite holiday traditions are...what do you to that they like, what would they like to stop doing, what would they like to start doing? Asking them these questions might help you to gauge what their perception of the holidays is, which may boost your own spirits. I was surprised to find that my kids consider our Christmas Eve dinner, where I started inviting my parents and siblings over after Mass for a casual meal, is a tradition cast in stone for them and something they count on. They also really like monkey bread and cocoa on Christmas morning. There are plenty of things that I was spending time and energy on that they didn't even notice. And things that I did almost as an afterthought that were important to them. So you won't know their perspective until you ask - and for all you know, those huge extended family celebration that you remember fondly might have been something that your own parents thought were a hassle.
Anyway...it sounds to me like there is something else going on. You wrote "Its so hard to go from uncondtional love and seeing these amazing people regularly" like the transition happened yesterday and yet you've been married for 18 years. You've been holding on to this sense of loss for 18 years? That's too long. Find out what else is triggering this so that you can relax and enjoy this season being grateful for what you do have. Life is too short to be in perpetual mourning during the holiday season.
