BADLY need your advice! Help!

I don't know where to start but lately I haven't been feeling like myself. I don't want to be around people. I don't feel like doing anything like going to gym. All I want to do is stick around the house and do nothing. I'll watch TV then suddenly I'll get bored and then I'll scroll through FB. The other night, I was pretty scared as the left part of my chest becomes so painful and tight. It also turns out that I skipped my period, I took the test and I am not preganant. I've been binge watching for almost 3 weeks now. I also been feeling like vomiting and I get pain in my stomach, sometimes I would even feel that left part of it is shaking. I should also mention that I've had a miscarrage in March and got my first period after mc.
I don't know what to do :( please advice. I'm planning on checking out a doctor but I don't know which department I should go.