Like everyone else has said, it is not the daycare that will put a strain on your relationship with your son and the attachment you have worked so hard at. Spending quality time with your son when you are together is what will continue that attachment bond you have. I am a single mom and work 40 hours a week but Caleb has a stronger attachment to me now then a year ago, but he is also very independent and outgoing.
I think more than anything, the reason I have some resentment toward daycare is they get to spend more time with him. And get to see some 1st's that I might not. But I also know the time I get with him is quality time.