Milk supply and stress

My husband was away on business this past week and the entire time he was gone I couldn’t pump more than 2 oz per session (typically I can get to 4 oz) I was trying so many things including legendairy supplements, water, coconut water, heating, etc. It was a horrible 5 days where nothing seemed to work. Now he’s back and I’m suddenly back up to normal... has anyone experienced anything like this? I’m wondering if it’s the stress of not having him around but if it’s stress I’m worried about what’ll happen once I’m back at work. Any experience or advice would be appreciated!