Can I talk to the clinical psychologist and my boss about another coworker?
Would you prefer to speak directly to the colleague involved?
No, I don't want to create tension or problems within the group
It's understandable that you don't want to cause tension amongst your co-workers. If talking to your boss instead is the best and most professional way to handle your concerns, then that is what you should do.
I took it out to my assistant/the receptionist. I complained about my colleague being a homosexual, since he didn't fit into the job description
In the future it would be better to go to your boss or the HR department. I don't believe your assistant or receptionist will be able to properly handle this situation with the authority it deserves.