Just Found Out I'm a Mistress

So I'll try not to make this a long drawn out story, but I feel so alone and am embarrassed of my current situation and looking for nonjudgmental input:

I'm a fit and good looking early 30 year old single mother. I'm 7 years free of a controlling and abusive relationship and never thought I wanted to date again. It took me 2 years to even be interested in having coffee with a man.
I'm an ER nurse and meet lots of men: cops, firefighters, doctors, etc but have never been interested in dating in my same field. That was until one day a new face came through. I was instantly intrigued by his demeanor. I could not figure out what was so attractive about this guy. I didn't see him again for several months until I was teaching at another hospital nearly an hour away and ran into him. We chatted briefly and parted ways. Awhile later I received a Facebook request from him and things progressed from there.
He is a father of 2 children. He's very involved in their lives and told me that he was still legally married but had filed 3 years before but never followed through. He was the most caring and loving man I had ever met. He showed interest in getting to know my son and my family. I met his kids and they would come over for dinner (preteen age), helped me move, playdates with the kids, etc. Everyone in our related field knew we were dating, he'd embarrass me with cheesey 'I love you's' on my Facebook. We were planning our future together but he expressed his interest in getting married-something I didn't want. I wanted a 'life partner' but not a husband. He was really upset and we cut ties for a brief amount of time but couldn't stay away. I told him id consider it but that he needed to move forward with the divorce. Things seemed so great!

2 years of dating later...

I start receiving multiple phone calls from a blocked number-15 in a row at times. I figured it was my son's father and I changed my number. I then started receiving calls on my new number. I finally answered and it was my partner's wife. She claimed to have been married to him for 23 years and told me that they lived together. She actually said a bunch of vulgar and inappropriate things, but I tried to explain that I was under the impression that they were getting a divorce. I talked with my partner and he confirmed that they did live together but that he was planning on ending things. He said that they live together but weren't really 'together'. They did sleep in the same bed and she had gone on his family trip. Ugh. I was so confused! Betrayed! Weirded out because I had a relationship with his kids...weirded out because I'd been to his house several times (man cave), we'd switch cars periodically, and he'd stay the night at my house.
So here's where I'm at now...the wife is living in a different city now. He tells me that he wants to be with me and that they are going to file again in 3 months. This sounds all good however, the wife is continuing to harass me. She has called my work and hacked into his facebook account and pretended to be him to get my address. I don't want to take the legal route with her, but I don't know if and when she will leave me alone. It makes me question whether or not he's even telling me the truth sometimes. She left another voicemail yesterday telling me that I 'must feel good knowing that he chose me over his family'.
I initially ended things but we found our way back together. I truly love this man but am worried that I'm being stupid. Here's the crazy part though....we haven't even had sex. He's had an 'issue' that he finally went to the doctor for and was told he just has 'performance anxiety'. This makes me think that he truly loves me too since we aren't together for physical reasons. I would really like to have a physical relationship with him but am currently content with the emotional fulfillment that I get from him. I don't want to wait anymore for him to file. The wife has blatantly told me that she's not going to divorce him and has made threats of violence towards me. I consider myself a very moral person but I'm having no guilt over this situation. The wife wants him to not date until the divorce is finalized but I feel that the marriage has been over and the only thing tying them together is the legal piece of paper. I worry that if we end things to appease her, that the divorce process will not progress.
Am I a fool if I wait? Will he really follow through with the divorce? I was hoping that he would file for divorce because he wanted to, not because he met me. He said that one time and I was not flattered. I'm just an easy target to blame for the wife right now for her failed marriage.