Can someone please talk some sense into me? I can't bear this anymore

[PennyDreadfull]

For context, my DH cheated on me 6 months ago. He carried it on with someone at work for four weeks before I found out. We went through a lot of tears, emotional discussions, and soul searching before I decided to reconcile with him, as I could see my way to forgiving him. (I understand why the affair happened, although I will never condone his actions).
Currently working things out and taking it one day at a time.

We both recently started new jobs.
I've been at mine for 3 months now.

I work with a man who I've been getting very close to. We are the same age, we have exactly the same likes, interests, and just totally click on so many levels.
He is the kindest, funniest and nicest man I've ever met and is totally gorgeous on top of that.

He also has a girlfriend. I have always known that and he also knows that I'm married.
We talk a lot and I see him every day obviously, we sit together and there is a huge emotional connection between us both. He knows about what I've been through.
We text sometimes at weekends but not all the time.
There is a flirty element in our conversations at times but he normally conducts himself well. For example last week I asked him if he wanted to go to the cinema with me after work to see a film we were both dying to see. He replied kindly that his girlfriend would feel weird about him going out with me. Fair enough.

My problem is this. I am totally and utterly crazy about him. I can't stop thinking about him. My heart flutters when I get a text in case it's from him. I look forward to going to work because I know I'll be with him all day. I fantasise about us being together constantly. I replay our conversations. I relive what he says to me.
His texts are never particularly flirty in the sense that he doesn't put kisses. Our banter at work can get a bit innuendo laced however.

I texted him a few days ago asking him if there was anything happening between us and he replied saying he thought I was a really nice person and we get on really well but he's sorry if he gave me that impression.

I'm miserable. The fact that he's such a great guy and isn't going to do the dirty on his girlfriend is making me feel worse.
I have to see him every day. I compare him to my husband who cheated.

Will I always feel like this? My feelings for him are so strong but there's nowhere for them to go is there?

Is this because of what my husband did to me?

DH is oblivious.

You've got my sympathy OP.

There are a lot of factors in play here and, yes, a fair bit of bad behavior, mostly on your H's side but also on yours, but I'm going to put that mostly aside as I reply to you.

Did you have counseling about the affair? I suspect you didn't. Can I suggest that the tears/deciding to reconcile etc was actually hysterical bonding. Have you heard of hb? Please google it and think about it.

What it comes down to, in my mind is that your H cheated, and it's really possible he only stopped because he found out. Am I wrong?

If I'm right and you agree with me on some level, I would say it's really likely that, in your grief regarding facing up to what is essentially the end of your marriage (sorry), you reacted as many do - with hysterical bonding. As an attempt to stop this awful change from happening.

And you may now be coming out of the fog a bit, and wondering wtf you were thinking. And, whether you consciously want to or not, on that very same deep level, you may already be looking for another partner because you can tell this partner can't be trusted.

Maybe that rings true for you. Maybe not?

Do you have children with H?
What is the balance of power like in your marriage - who earns more?
What is the balance of unpaid work - who contributes more to family life (time, attention, housework, planning)?
What is your sex life like?

After all those questions - I will say that while I have an opinion / instinct based on what you have written - I may be completely wrong. I do think you need counseling. You, separately from H, at the very least - ideally, you need individual counseling AND marriage counseling.