<human>: Summarize the given text in a few sentences.

I have been friends with Sean and Kate since college. They got married about 3 years ago and I have been hanging out with them steadily since then. 

I am single. I don't think this should matter, but perhaps it does. I see them once or twice a week for game night. It's always just me and them. I watch their dogs when they go out of town anytime they ask because I love them and I love their dogs. I never get invited to couples nights out or their other college friend get-togethers. This usually does not bother me because I guess it's a couple thing and I just don't fit in. It always seemed like they wanted to keep me separate for this reason, but after this incident, I no longer know how to feel.

Today I was going through my Instagram and I saw a post from her. It was flowers and basically said how thankful she was for her friends (which was about five girls from her inner married circle, most of whom do not even live in town) and that they cared about her when things went wrong. I immediately texted her to ask what was going on. She informed me that she had gotten in a car accident with her mother that resulted in injury. This was old news to her as she explained what happened. I became upset (not directly to her, but after the fact) and questioned (to myself) if I mattered enough for them to let me know about this at all. I feel like I do not matter enough in their lives and this is the realization that hurts me the most. How do I let them know how I feel without making the situation about me, because I am sure she is reeling as it is.
<bot>: friend got in car accident and I find out about it much later, making me feel our friendship matters much more to me than it does to her/them