Issue of trust re coworkers (and everyone else on earth)

Thank you 3 who replied with feedback. I guess the issue is really having no reliable gut instinct about who to trust and reveal selfs to.After working closely with this coworker for almost a year I think maybe my immature goodwill was exploited by him. He encouraged me to think we were friends and revealed something of himself (each time exploiting my sympathetic response but to his own good on the job) and I over-reciprocated because I felt honored to be called friend. He has seniority on the job but after leaning on me to callude with him in trying to get someone else fired he had no more use for me or a personal friendship so I asked him if he exploited my positive regard for his own career goal and he no longer speaks to me. My gut says I was exploited but just as strongly it answers your socially ineptand hopeless so grow up!
Am I doing these postings properly? I'm new at this.