I can't let go

I can hear my mom's voice in my head saying "Don't let him sleep in the bed with you. It's going to be hard to get him out later on." Well those words of wisdom are ones that I should've adhered to. Five years later, and my son still wedges himself between my husband and I every night. I don't think I can let go.
For 3 years my husband was away for law school, so my son's crib/bed was always in my room. As he got older, he slowly began to take over a side of my bed. I sometimes think it was more of a comfort for me rather than him. Having his little body next to me at night gave me a feeling of immediate joy. Now as he's gotten older, the foot in my back or intermittent slaps on my face have gotten uncomfortable. When he turned 5 last month, we purchased a new twin size bed and placed it in his own room. Of course, my wise little guy said he couldn't sleep in there yet because the room wasn't painted and we weren't finished setting it up. Well hubby has painted it today & in a few days it should be all set up.
But am I truly ready for the separation? Is this how parents feels once the kids head off to college? I have a feeling of anxiety about not having him near me while I sleep. I will no longer be able to stare at his little face & watch him sleep. I think this move will hurt me more than him. I'm looking forward to the space and the privacy that hubby & I will get but my heart breaks a little. This is just a step into my little boy's move to becoming a big boy. I don't know if I'm ready for it. AAhhhh the trials & tribulations of being a Mommy.