I'm not happy with myself..

I'm not happy with myself at all & I don't know what to do to change. I try to pick up new hobbies and things to occupy my mind but all I do is sit around and think suspiciously of my boyfriend. I try to work and I can't focus, I try to do my hobbies and I can't focus on that either. It's ruining literally every aspect in my life. Because of this suspicion and anxiety that comes with it, I hate leaving the house. I stopped hanging out with friends and family and just hide in my house. I don't remember the last time I had girl talk or socialized outside of my relationship. I don't know how to get back on track. My weight has dropped drastically so my body sucks right now which makes me even more self conscious and when I eat it's only to calm my stomach down.. I don't enjoy it like I used to. 

It's much deeper than this but has anyone ever felt this way? If so how did you overcome this..

I'm 25 btw, never been depressed or had anxiety before 23..