How do you know when you are emotionally unstable? For me, I know by one feeling: Debilitation.
I can recall two extremely unhealthy emotional seasons of my life and both included this emotion.
During these two seasons of my life, I successfully ran away from those who knew and loved me; not physically, but socially. I would make excuses to not spend time with those closest to me simply because I didn't feel the need. I created the habit of saying no to social gatherings and one-on-one coffee dates with friends.
It's a lot easier to feel debilitated when we're often alone. Over time I felt like a tree with no leaves, like human without my humanity. The thing is, we are meant to be social creatures. People inspire, people hurt, people love, people care, people remind us of our natural humanity. So what happens when we don't allow ourselves to be around people? Emotional unhealthiness.