Okay, so first. I understand how you feel. I remember finding my W's online dating profile last January. It was especially hard because it was just 5 days after she started showing signs of wanting to stay in the MR.
I wouldn't fixate on the W4W/W4M thing. I will speak to the potential that she might be gay or bi in a minute, but reaching out to others, male or female, is still problematic. I know when my W's picture came up on the dating site, with a full dating profile, my heart dropped into my stomach. Up to then I didn't realize the depth of her waywardness, and only thought that my being so absent for so long had just opened up for someone else to swoop in. That she was actually actively out looking was a huge wake-up call. I found this this board about 3 weeks later and the term wayward stuck out to me like a sore thumb.
Is this is a big deal? I would say it is. Does it change what you should or shouldn't be doing? No.
I will say that if she is having bi and/or gay feelings then this could potentially speak to why she has been so depressed and withdrawn. Most WAWs feel some level of stuck. I would imagine that when it comes to sexuality, no matter what is causing her to question it, her feeling of being stuck must be off the chart. With being married, having kids, and feeling like you should be with the same sex, that has to be a struggle. I would encourage you, no matter what you decide, to give her the time and space to figure her stuff out.
Whether or not you confront is up to you. I confronted because this profile was very public, and our D (at the time 14) had no idea that there were any problems between us. When I confronted I was very firm, not sad or mopey, and stated that I felt it was disrespectful for her to have a public, full view, picture and all, dating profile. And that if she cared one iota about how our D found out about our potential split-up, she would take it down.
JS, hang in there buddy. I know this is a blow on multiple fronts, but it really doesn't change what you should be doing. Unless this is the final straw that makes you want to pull the plug. Otherwise keep on DBing. But think about what I said about how I confronted my W about her dating profile....especially with kids. Any of their friends' could end up seeing that profile, and then showing it to them.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018