advice needed please! Greatly appreciated!

Hopeing someone can give me some advice

I was talking to this guy around this time last year (Jan/feb). He did used to work with me, but no longer. I really liked him, the vibes were really good and he was just a m genuine person. we hung out three times and on the last time we hung out we went out for dinner. He dropped me home and I gave him a side hug as I got of the his car. From that night everything changed. He wasn’t talking to me as much and become more distant. I gave him a few days, but it was really messing with my head so I messaged him asking if he was okay and why he was acting so distant. He pretty much just said that he wasn’t feeling that connection anymore like he was at the start and apologised for the lack of communication.

Fast forward a year later I still really really like him.

It was such a coincidence cause a night ago I went to this concert and was catching the train back home with my brother. There was no one at the station except us until 15mins of waiting the guy and his 2 friends show up and sit across from us. We spoke a little bit. I woke up the next morning with such a heavy heart thinking it was all a dream.

I talked to my bestfriend and she said that I should message him and ask if he would be interested to go out for lunch as friends, test the vibe and see if there’s anything there. She said that I’ve got nothing to loose as he no longer works with me and doesn’t want me to regret not saying anything. I feel like I want to just don’t know how to word the message and kinda worried how he would react.

I really need some other opinions if I wasting me time and energy in messaging him, just really lost in what to do.