Can’t find cause of angioedema affecting the lips. ?

For about 2 months I’ve been getting random swelling of the lips (sometimes bottom, sometimes top) which almost always starts when I go to bed. By the time I get up in the morning, my lips look like balloons they’re so puffed up. They’re usually back to normal within around 10 hours but I can’t figure out what’s causing it. 
I’ve recently had a blood test taken at the doctor’s so that might give me some answers but I’ve read that often this kind of thing is idiopathic. I’ve never had food allergies before but I’m not sure what else it could be.
I’ve been under a lot of stress recently - could this be a cause? I’m just terrified it’s going to get worse and start affecting my tongue and throat and I won’t be able to breathe. I take anti-histamines and ibuprofen for it but I’m not sure if it’s helping much. 
I’ve also had swelling on the hand and also the feet on occasion. But the lips thing is by far the worst. Any ideas would be greatly appreciated. I’m a 27 yr old male, no underlying health conditions.