Very, Very Lost

I feel so lost right now. I thought I knew what I was doing and where my life was going but my plan as seem to fall apart in every direction. I firmly believe that if you're not happy with the way your life is going that you have every right to change any aspect you're not happy with. So that's what I did. I wasn't happy where I lived or what I was doing with my life so I quit school, moved back to my home town, moved in with my best friend and I can see my family when ever I want to. From the outside things would seem good, but I still have this empty feeling inside. I don't know what's missing and it's eating away at me every day. I find myself more quiet and calm than usual. I don't understand this feeling. I have amazing people in my life, my heart it set on someone so special, but why am I still not happy? 

This feeling really bothers me because I cannot seem to figure out the reason for this sadness and empty feeling. Is this what life is supposed to be like once you're on your own? Is this feeling going to be permanent because I can't live with this feeling anymore. I lived with depression my whole life, I know what it feels like to be on the edge of wanting to end my life, I know the feeling of abandonment and how it feel to know you let people down. But this feeling, it is not familiar. I struggle to find happiness when I am alone. I am happy with everything in my life right now. I overcame depression, I have gained my self esteem and confidence back, I love everything about my life. Why must this feeling arise when I am alone? What have I done or not done to make this feeling so unbearable? I need to figure out what I am missing because I am afraid that I am not missing anything and that this is the way my life will forever.