Steve, whatever you decide, I wish you luck. Your story about the 2nd of the two women, the one you can’t stop thinking about, is eerily similar to a situation I was in last Spring. It flatlined when school let out (she has 2 pre-teen daughters). Enough on that, this is your thread, not mine.
Re the recent woman who is flaming you over texts, clearly she was hurt, or maybe she’s just a psycho. Most people can be great and a bit awful too, as you said about your ex. Maybe you are to her what “woman #2” is to you. Every who dates has to understand that they can hurt, or be hurt by, someone else. So don’t feel guilty – you saw as soon as you could that it wouldn’t work for you, and let her down fairly gently.
Peace.