People are trying hard to explain why taking any action will backfire.
Email him at work - he shows his manager & HR, citing harassment in the work place, you could lose your job, then struggle to get another job as gossip spreads.
WhatsApp - he confides in friends, maybe even shows his wife, the message sent by an unstable girl at work who got the wrong idea, now you won't leave him alone. Again possibly affecting work and/or possibly getting you a warning about harassing behaviour from the police.
Text - see above for WhatsApp
Do you think he'll see that he's hurt you and apologise, or even think oh I made a mistake, she is the one for me?
By all means, look at gas lighting, look at narcissistic behaviours and see if that applies to how you've been treated. Then if you need too, you can go to your manager or HRA/HRM, backed up with information evidence. Don't think that unless you work in the same team, that they'll take action as you've had a fling. Even then unless it's an abuse of power etc, action is unlikely to be instigated.
As I said focus on your self love and your self care. Repair the broken bits then look for someone who is single, someone who hopefully will show you all the things your co-worker didn't. Like oh just a minute phone call, got to go now and go back to my wife!
Did it ever enter your head that this wasn't viable and it was wrong?
If you'd said what you're saying now earlier on, maybe the responses would be different. It did appear like you enjoyed the fact that you'd post leaving a few crumbs to follow. That really does not go down well. If you were expecting implicit sympathy, you can't have seen what happens on AIBU. People go for the jugular.
So self love, self care, move on, look for someone new. Leave it to the husband or a colleague/friend to maybe let his wife know.
I knew if a woman who should have known better, she would sit in our local gushing over this bloke. Many regulars pointed out to her, this is wrong on so many levels. She even declared her love for him, she told people the hubby had said his wife is an ogre. No matter how hard you explained, he would say she had two heads, if that helped him justify his actions. OW left the area, husband was still around, people would say what were you thinking. OW dropped the husband in it a certain way, that made the wife suspicious. OW had created a whole narrative in her head why they were going to live happily ever after. I stopped talking to OW at one point, as she was 'shocked' others would talk about it.
Please let this sink in.