"I'm in too truthful a mood"

Since April 2009, I've had about 7 close friends and family members become engaged. I'm talking best friends. And it wasn't that hard to hear until the last few.. (Please don't doubt my genuine excitement about each engagement.)
But it's hard not to compare my life to the lives of my friends. It's hard not to question the sovereign hand of God and his will for my life.
Last night, my roommate Paige and I were talking across the room, each of us sitting on our beds, ready for sleep but not at rest. I told her that I do believe I gain a greater intimacy with the Lord by being single. But lately it's been hard to believe that singlehood is what God desires for me. I think about Eve and how she was created to be Adam's companion, to complement him.
Then the LORD God said, "It is not good that the man should be alone; I will make him a helper fit for him." Genesis 2:18
It is so clear to me that God built us desiring relationships because he wanted to be in relationship with us.
But this also makes it difficult for me to know if it's just my sinful heart that desires what my friends have, or if it is the true, God-fearing and freed heart of mine that desires companionship and a relationship reflexive of Christ and his church. Or, I'm just scared of losing all my friends to their future husbands. (I know that last statement is not true in its entirety, but I have seen it to be true to some degree, and I accept that. But it does not make it easier.)