Do I have a mental disorder for not wanting my kids to grow up?

My oldest son just turned 18 and I have been really emotional and the thought of him actually leaving is a very tender subject. I feel really nostalgic for his childhood. I don’t remember my parents acting this way when me and my siblings came of age. When other parents tell me this is great that he is getting so old I just feel sad and I want to tell them it is not great. Does anyone feel this? Edit: I am in my 30’s so a lot of parents my age have no idea what it feels like to have a kid turn into an adult. They all think it’s awesome because that time is far off for them. For me, it went too fast and now I’m hurting. Like I feel a physical loss and my chest hurts type of hurting. via /r/Parenting https://ift.tt/36Gow2D