As my dad is fond of saying, no matter how horrible your life is, it can always be worse. Always. So while bad things can and do happen, on the scale of all that's possible, they usually aren't all that bad. Heck, you can usually learn something from them too, and I'm sure many people would agree that having bad things happen to you is a necessity to becoming a good, well rounded person capable of recognizing all the good around you. After all, if you've never been in the shadow, you can't see the light.
If that's what you want to do, keep working at it.
People often lie to themselves and others as a way of coping with bad situations or relationships without realizing they are doing it. I have several friends like this. Of course there's always the possibility that they aren't lying at all and are truly happy.
Life ain't fair. Don't expect it to be. You don't get anywhere in life just because you're a good person. It takes work and dedication to get what you want, whether it's a job, a relationship, friends, etc. If you want friends and relationships then you need to be proactive and go out and meet people. Trust me, I know. I have no close friends within about 1,000 miles of me nor am I in a relationship. But that's mostly fault. I have the option of going out and meeting people, I just choose not too usually.
One thing I would recommend is to see a psychologist. I saw one for a little over a year for therapy involving ADHD and a language disorder, but she also helped me recognize that I am the one in control of my life and I have the power to change it. She gave me exercises to do and taught me coping skills to help deal with a variety of stressful situations in a healthy way.