It is difficult sometimes to separate ourselves from our children. We hurt when they hurt. The problem is, we have no control over how our children will deal with the hurt, so we feel a total lack of control. You said that yourself, so you clearly have self awareness.
It’s normal to want to fix everything for our kids. It’s normal for us to want our kids to have perfect lives. As parents, though, it’s not our job to do that. You feel like you have so little control because you don’t. And that’s okay.
I strongly suggest therapy for you. I remember how stressful the college search was … and believe me, things will get more stressful after they go away. My D had a rough first year, and it would have been incredibly difficult for me if I didn’t know how to deal with my own feelings. Please consider getting some assistance in learning how to cope with this stage of parenting. The goal is to enjoy the journey, and if you need some support to get yourself into that frame of mind, it’s wise to find it.