How does a mom let go!!??

About a week ago driving my 20 year old (no drivers license yet because of his own laziness) told me "Mom, after my 21st birthday I am moving to upstate NY . My first thought was ... yeah ok, he needs me to do his laundry, he hates being away from home longer than 2 days. But as he was speaking I heard the passion in his voice. I need to reverse in order for this to be understood. About 9 years back, I had issues with myself, I knew he had to go to my ex husband for a while. I had to be able to take care of me before I can give a thousand percent to my children. Although it broke my heart~all of them went to NY to live with their Dad. My oldest 2 eventually moved out and got their own lives. My eldest son 27 is living very well on his own self supportive and has a fantastic job in the  city and in school paid by the company he works for.. also union employed. My daughter 25, now a mom of her own living in Jersey with her fiance, and a happy family. My 23 yr old he is not on the wrong track but also still unsure where life is going to take him. I also have joint custody of my 13 year old daughter. Lives with her Dad, who still lives in his parents house... that again in a future blog. Now when I moved back to NY in 09.. Joseph was having issues in all situations. I tried to have him in therapy and he was not having it.. I had him in school speaking with his guidance counselor on a regular basis. Joseph was not  giving a rats ____ about anything dealing with rules. If they said left~ he went right. I knew at that point if I didn't take control it was only going to get worse. That is when I signed him into Military School. Joseph went away for 6 months. I wrote him everyday. Spoke to him once a week. At the end he thanked me for doing it. Graduated with a HS Diploma. He then moved in with me. Joseph's dream was culinary school.. I.C.E. We went back and forth so many times. My credit was shot due to my ex and other issues. I asked family members if they would co-sign for school. Lots of them said YES we will be there!! Of course!!! Until the day where it came down to signing the paper work. Everyone backed out. It broke his spirit and broke my heart. The dis appointment was all over his face-attitude-EVERYTHING.. I then said we save up and try again in a few years. Fast forward 6 months. This is when he said (and again with so much passion) I am moving upstate after my birthday. I said "Nope-you are NOT!" Joseph then said " I have to grow up, I have to try, I can't live with you forever!"  He has everything mapped out, getting his dl before he leaves, taking a transfer from his job. Also saving up $$ a few months rent  before he leaves. How do I let my son go??!! My heart is breaking.. I know he wants it and I know he is going to follow through. I know it is a drive away (3 1/2 hours) but how do you let them go? How do I not cry and wonder will he be ok...This will be a blog... a soap opera.. a drama and a comedy!!! To be continued....