I have the same problem. The more I sleep past 7 hours the shittier I feel for roughly the number of overslept hours. If I sleep 12 hours, I'll feel foggy and g

I have the same problem. The more I sleep past 7 hours the shittier I feel for roughly the number of overslept hours. If I sleep 12 hours, I'll feel foggy and groggy for 5 hours afterwards (12-7=5). I think it is serotonin related. I force myself to not sleep more than 7 hours.