I always assume the worst about everyone in my life.
Why do you assume the worst about other people?
I used to trust people years ago but I was betrayed.
I understand that people betrayed your trust in the past but try not to be so cynical about it. Definitely you should be cautious but should not distrust every person around you.
People can't be trusted these days.
You should talk to someone about your trust issues. I know you've been hurt in the past, but you can't assume that everyone will continue to hurt you. You're missing out on a big part of life if you don't make connections with others.