Need some advice. (TLDR @ bottom)

Married 10+ years, lots of good times, very few major arguments. Lots of bickering over small things and nit picking. She dated lots of "bad boys," so her family was super excited when we got together. I think it worked because I was a mix of mostly "nice guy" with ambitions, and just enough "bad boy" to be palatable for her. She knew she would have a pretty comfortable life. I was never an Alpha, but definitely had a lot more qualities before marriage. Ended up slowly going beta over the next few years.

Sex life:

Typical sex life story... great before marriage, slowed down shortly after tying the knot, then took a big dive after our first kid. "I don't feel sexy anymore." Figured it was par for the married life course. Spent the whole time doing the BP thing and trying to guilt her into sex because we were married and it was her duty. So of course I got drip sex when I pouted enough. Like everyone here, I wish I had found out about the RP concept long ago.

Red Pill:

Started down the path about a year ago. Followed all the guidelines, started feeling great about myself, and stopped trying to please her. She flipped out. Couldn't handle the change. Actually used the words "This is not who I married, I married a nice guy." Kept plugging along and doing my thing. After she got over the initial shock, I started to notice results about a month into it. Much better sex life, less bitching, started doing nice things for me, and buying me stuff. It was always the other way around. Crazy how well it works.

Finances:

Started a new business a couple years ago, and due to getting it up and running, I work a lot more and make about 20% less. This has caused a lot of stress on us both. I'm not happy about it, but know it will be much better in the long run. She's talked about not being happy for a while, but only recently started bringing up the possibility of splitting up. She finally showed her cards and implied that she "can't live like this AND not have any money." Basically her comfortable life was no longer as comfortable so she is ready to jet. I was pissed!

Therapy:

She started seeing a therapist a couple weeks ago. It was long overdue, even if only for several stressful events (outside of our relationship) over the last few years. Since then she's been more open with me. Finally came out to me that she doesn't think we have, or have ever really had sexual chemistry. Not that we haven't had a good sex life, because she says I can always make her orgasm, but basically she's had better sex with one (or probably several) of her previous 11 partners). It was huge blow to my ego. Then I was more upset that she's waited all these years to tell me. Not giving me chance to work on things, but instead having lots of obligation sex with me.

Suspected of Cheating:

I have always trusted her. Don't look through her stuff, don't care when I go out of town, or if she goes out dancing with her girlfriends. Really trusted her completely, and always lived by the fact that it wasn't worth the mental energy as long as nothing was super obvious. Then out of the blue, 2 months ago, I asked to look at something she was talking about on her phone, and she hesitated, did something else on it, then gave it to me. Wasn't a big deal, but gave me a strange vibe. I dismissed it, and made a point to not go snooping, because that's not me. Then I started to notice her being more and more weird about her phone. She never used to care where it was, now all the sudden she was on it all the time, and would literally take it in and set it on the edge of the tub when she showered. Major red flags. So I started to find excuses to need to use her phone for something, just to see how she re-acted. She would get weird, and then start talking a lot more and being overly happy. Finally over the weekend, I used her phone to call someone, and the last txt was from her personal trainer. When I opened it, there were only 3 txts from that day. I was sick. Got on Verizon and pulled up her txt records. There actually hadn't been any txts to or from him in a couple weeks. Didn't want to ruin the weekend since we had lots planned with friend, so I waited until Sunday night. Confronted her without being an ass in case there was some explanation. Esentially: "I've never had doubts about you being faithful, and I'm mad that I've been worried lately, looked at your phone and there was only 3 txts from Douchebag Trainer. Why are you deleting txts from him?" She says she deletes txts to "clean up" her inbox. Told her that there were lots of other txts that she hadn't deleted, so that didn't make sense. She said it had been a while since she had deleted stuff. Point blank asked her if they were sending anything inappropriate, txts or pics. She said no. Because I had already looked at her txt records, and it had been a couple weeks since they had sent anything back and forth, I thought that could have been feasible. If something was up, I figured there would be a steady flow of txt history. I didn't have any proof, and if I pushed it anymore I thought it would make me look bad for doubting her if she was actually being honest.

Confessed To Cheating:

She saw her therapist 2 days later, and said she needs to get something off her chest. "I lied to you the other day, I have been sending stuff to Douchebag Trainer. I have feelings for him. We haven't done anything sexual but we have talked about it." Basically they've been "dating" via txt over the last 3 months. Talking about their day, telling him looked hot after their work out, at some point sending half naked (she says not fully naked) pics to each other, and the thought of hooking up. Because I know her schedule, and he's married with kids, I do believe her on them not hooking up. She takes care of our kids all the time, so it would have been nearly impossible for it to have happened. She said she couldn't take it anymore, and told him that they couldn't keep doing this, about 2 weeks ago. Txt history does back that up.

Need Your Advice:

Am I crazy for thinking she is genuine in wanting to work on our relationship?

How should I treat her or act around her?

I'm pretty sure I have the ability, using Verizon Messenger app, to see all of her deleted txts. Is that a bad idea, or am I just going to make myself more sick?

TLDR: Wife of 10+ years married me because I was a stable option with a future. We've had lots of good times, but it's been kind rough the last 5 years. She's been talking about the possibility of splitting up. Just told me that we don't have "sexual chemestry," and that my not making more money is making things a lot worse in our relationship. Have been trying to reconnect and get our marriage back on track, and she started seeing a therapist. Then told me she has feelings for her trainer, and they have had a txt (not physical) relationship over the last few months, but she called it off 2 weeks ago. -- What do I do?