Did I make a mistake

I had feelings for someone in the work place, I decided not to show my feelings to them because: I wanted to be professional , I didn't want to be a fool and I just didn't want them to know I had a crush on them - in case they told everyone on our team.

At the time, I think they liked me too. I think they knew it too. For some reason they lost their spark towards me, whilst I still had feelings for them and we just drifted apart.

I respect their decision

My crush is now really close to another colleague in the company, who I know.

My colleague is a very expressive person...and told me they liked "my crush"

I should've let my crush know I liked them, it hurts seeing them together.

I'm now trying to be positive. I don't have a crush anymore, they're just another colleague to me. Maybe this was the best thing to happen, maybe they knew I deserved better and they weren't the best person for me, so they just let me go.

I still have feelings for them, any advice on how to make it go away?

Did I make a mistake for not telling them how I felt?