I don't approve of my daughter's choice in boyfriend
Why? What is there that makes you disapprove of the guy?
I don't know. I feel like he won't make her happy, but maybe it is just me thinking too negatively.
You have doubts about your daughter's love interest, but she is the one who will have to live with him if they get married. Support her regardless of your thoughts and understand that it is her choice. If you get too involved things will turn out badly either way, she might even disown you for meddling.
I don't think that I can. It's tough seeing my baby girl move on from me.
It's part of life. You can't keep her in the house forever. It's not like she's dead, you can hang out sometimes.