Do not call! Do not let yourself. Take a quick walk around the building or down the street. Get a drink of water or hot tea. Do not call. He is fine. He isn't a 4yo you left home alone. He's a grown man. You can go 6 hours without checking on him!!
After you take a walk around, and get a drink, do some deep breathing and think quietly for a minute. Another adult does not need to be checked on every day, much less ever few hours! The uncomfortable feelings may come but this is the time you need to react with your intellect, not your emotions. The uncomfortable feelings are just that - uncomforable feelings. They won't last forever. They won't kill you. You must react with your *head* and your logic right now. The anxiety you have is not founded in logic. It is an emotion and feeling born of your co-dependence. You have reached a point now where you CAN make the shift from reacting on the raw feeling to reacting with logic and good sense - even though it feels umcomfortable. Let your logical brain win!!!
You can do that, just for today. I know you can. Post again if you need to - to keep rassuring yourself.