I think we need to better define what you expect (and expect to feel) from a relationship.
This link might help. At least as a starting point.
http://en.wikipedia.org/wiki/Triangular_theory_of_love
ponies wrote:
...live with them and feel comfortable with them... not minding being around the person and not wanting harm to come to them,
or look after them when they are sick or hurt...
So there are a maximum of three components to a relationship, and you've listed two.
*You are comfortable around them. This means you have intimacy.
*You care for them and want them to be well. This (I think) qualifies as commitment.
The missing component then, is passion. Sexual attraction. Either you didn't mention it or you haven't experienced these feelings yet. As others have mentioned, you could also be asexual.
The much celebrated and mythologized qualities of love can usually be reduced to the initial cascade of hormones which gives rise to strong passion. This often wanes with time.
It sounds like you aren't missing much.