Why I'm lonely

We've all been through ups and downs in life and not all of us can speak our minds.
I'm not the kind of person that can just talk to anyone about my thoughts and problems. No I can't talk to anyone because no one knows what's going on in my life. I've tried talking to people but it just seems impossible for them to understand. My life isn't completely shit, but it's close. It's not the people in my life, it's not the things they do, it's just me and my mind.