Anxiety levels are rising

This always happens. Its been 5 days since Ive last seen my child. I dropped him off at school Wed morning and I havent seen him since. Ive talked with him every day of course but there is still something about tucking him safely in bed each night knowing that hes in our house safe and sound. I dont have to worry that he will get up in the middle of the night with leg pains and I wont be there. Or that he will go for a walk up the street and someone will kidnap him( yes I worry about that) Or that he will have a bad day at school but I wont get to give him a hug and talk about it on the way home, or go over his homework, or be the one to kiss him goodnight that night. It happens every time he goes to his dads house each week. I start to feel this intense anxiety build up inside my chest and know that until I see him, hold him, and give him a big hug it wont go away. I try and play cool, but yesterday when I called him and he was on the phone talking normally and then went into a whisper so his dad couldnt hear and said in a small voice " mom I really miss you" I whispered back "Oh sweetie I miss you too- I be there right after school k? I love you!!" Im sure within the first hour when hes a grumpy stinker again Ill wonder what I why I was missing him so( haha ) but for now Im counting the next 7 hours till I can pick him up from school and see those adorable brown eyes!