I think it's sort of natural to want to tell people about what you perceive as good things going on in your life. So your co-worker telling you about her date was about her saying things that reinforce her good feelings about her date, and probably she didn't even have a clue that it might upset anyone.

And yes you can be in therapy and in a relationship if that is what you want and what you are ready for.

And it's OK to be single too, but how to be OK with yourself in any stage of a relationship isn't something that I have much in the way of good advice about.

But in general I would say don't get into a relationship that you don't feel ready for. And don't judge yourself by what others are doing, be you, move at your rate, you control your life not the rest of the world.